Defining perioperative mortality after open and endovascular aortic aneurysm repair in the US Medicare population

Long-Term Outcomes of Open Versus Endovascular Treatment for Abdominal Aortic Aneurysm: Systematic Review and Meta-Analysis With Reconstructed Time-to-Event Data

BACKGROUND

The advent of endovascular techniques has revolutionized the care of patients with uncomplicated abdominal aortic aneurysms. This analysis compares the overall survival and the freedom from reintervention rate between open surgical repair (OSR) and endovascular repair (EVAR) in patients undergoing elective abdominal aortic aneurysm (AAA) repair.

METHODS

PubMed, Scopus, and Cochrane databases were searched for studies including patients who underwent either OSR or EVAR for uncomplicated AAA. All randomized controlled trials and propensity-score-matched cohort studies reporting on the outcomes of interest were considered eligible for inclusion. The systematic search of the literature was performed by 2 independent investigators in accordance with the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement. We conducted 1-stage and 2-stage meta-analyses with Kaplan-Meier-derived time-to-event data and meta-analysis with a random-effects model.

RESULTS

Thirteen studies met our eligibility criteria, incorporating 13 409 and 13 450 patients in the OSR and EVAR arms, respectively. Patients who underwent open repair had improved overall survival rates compared with those who underwent EVAR (hazard ratio [HR]=0.93, 95% confidence interval [CI]=0.88-0.98, p=0.004) during a mean follow-up of 53.8 (SD=29.8) months and this was validated by the 2-stage meta-analysis (HR=0.89, 95% CI=0.8-0.99, p=0.03, I2=62.25%). Splitting timepoint analysis suggested that EVAR offers better survival outcome compared with OSR in the first 11 months following elective intervention (HR=1.37, 95% CI=1.22-1.54, p<0.0001), while OSR offers a significant survival advantage after the 11-month timepoint and up to 180 months (HR=0.84, 95% CI=0.8-0.89, p<0.0001). Similarly, freedom from reintervention was found to be significantly better in EVAR patients (HR=1.28, 95% CI=1.14-1.44, p<0.0001) within the first 30 days. After the first month postrepair, however, OSR demonstrated higher freedom-from-reintervention rates compared with EVAR that remained significant for up to 168 months during follow-up (HR=0.73, 95% CI=0.66-0.79, p<0.0001).

CONCLUSIONS

Despite the first-year survival advantage of EVAR in patients undergoing elective AAA repair, OSR was associated with a late survival benefit and decreased risk for reintervention in long-term follow-up.

CLINICAL IMPACT

Open surgical repair for uncomplicated abdominal aortic aneurysm offers better long-term outcomes in terms of survival and freedom from reintervention rate compared to the endovascular approach but in the first year it carries a higher risk of mortality. The novelty of our study lies that instead of comparing study-level effect estimates, we analyzed reconstructed individual patient-level data. This offered us the opportunity to perform our analyses with mathematically robust and flexible survival models, which was proved to be crucial since there was evidence of different hazard over time. Our findings underline the need for additional investigation to clarify the significance of open surgical repair when compared to the latest endovascular devices and techniques within the evolving era of minimally invasive procedures.

One-year safety and effectiveness of the Alto abdominal stent graft in the ELEVATE IDE trial

OBJECTIVE

This study reports the results of a prospective, multicenter trial designed to evaluate the safety and effectiveness of the polymer based Endologix Alto Stent Graft System in treating abdominal aortic aneurysms (AAAs), with sealing 7 mm below the top of the fabric in aortic neck diameters from 16 to 30 mm.

METHODS

Seventy-five patients were treated with Alto devices between March 2017 and February 2018 in 16 centers in the United States for infrarenal AAAs (max diameter ≥5.0 cm in diameter or size increase by 0.5 cm in 6 months or diameter ≥1.5 times the adjacent normal aorta). Patients were followed for 30 days, 6 months, and 1 year by clinical evaluation and computed tomography and abdominal x-ray imaging. Treatment success was defined as technical success and freedom from AAA enlargement, migration, type I or III endoleak, AAA rupture or surgical conversion, stent graft stenosis, occlusion, kink, thromboembolic events, and stent fracture attributable to the device requiring secondary intervention through 12 months. Preoperative characteristics, perioperative variables, follow-up clinical evaluations, and radiographic examination results through the first 1 year were analyzed.

RESULTS

The mean patient age was 73 years, with 93% of patients being male. The 30-day major adverse event rate was 5.3%. At 1 year, the primary endpoint was met with a treatment success rate of 96.7%. Through 1-year post-treatment, all-cause mortality was 4.0%. No AAA-related mortality occurred. AAA enlargement was 1.6%, type I endoleak rate was 1.4%, with 100% freedom from type III endoleaks, device migration, device fracture, stent occlusion, or AAA rupture. The device-related secondary intervention rate was 2.7%.

CONCLUSIONS

This prospective study demonstrates the Endologix Alto is safe and effective in treating AAAs with appropriate anatomy at 1 year. The safety endpoint is met by a 5.3% 30-day major adverse event rate, whereas the effectiveness endpoint is met by a treatment success rate of 96%.

Editor's Choice - Optimal Threshold for the Volume-Outcome Relationship After Open AAA Repair in the Endovascular Era: Analysis of the International Consortium of Vascular Registries

OBJECTIVE

As open abdominal aortic aneurysm (AAA) repair (OAR) rates decline in the endovascular era, the endorsement of minimum volume thresholds for OAR is increasingly controversial, as this may affect credentialing and training. The purpose of this analysis was to identify an optimal centre volume threshold that is associated with the most significant mortality reduction after OAR, and to determine how this reflects contemporary practice.

METHODS

This was an observational study of OARs performed in 11 countries (2010 - 2016) within the International Consortium of Vascular Registry database (n = 178 302). The primary endpoint was post-operative in hospital mortality. Two different methodologies (area under the receiving operating curve optimisation and Markov chain Monte Carlo procedure) were used to determine the optimal centre volume threshold associated with the most significant mortality improvement.

RESULTS

In total, 154 912 (86.9%) intact and 23 390 (13.1%) ruptured AAAs were analysed. The majority (63.1%; n = 112 557) underwent endovascular repair (EVAR) (OAR 36.9%; n = 65 745). A significant inverse relationship between increasing centre volume and lower peri-operative mortality after intact and ruptured OAR was evident (p < .001) but not with EVAR. An annual centre volume of between 13 and 16 procedures per year was associated with the most significant mortality reduction after intact OAR (adjusted predicted mortality < 13 procedures/year 4.6% [95% confidence interval 4.0% - 5.2%] vs. ≥ 13 procedures/year 3.1% [95% CI 2.8% - 3.5%]). With the increasing adoption of EVAR, the mean number of OARs per centre (intact + ruptured) decreased significantly (2010 - 2013 = 35.7; 2014 - 2016 = 29.8; p < .001). Only 23% of centres (n = 240/1 065) met the ≥ 13 procedures/year volume threshold, with significant variation between nations (Germany 11%; Denmark 100%).

CONCLUSION

An annual centre volume of 13 - 16 OARs per year is the optimal threshold associated with the greatest mortality risk reduction after treatment of intact AAA. However, in the current endovascular era, achieving this threshold requires significant re-organisation of OAR practice delivery in many countries, and would affect provision of non-elective aortic services. Low volume centres continuing to offer OAR should aim to achieve mortality results equivalent to the high volume institution benchmark, using validated data from quality registries to track outcomes.

Epidemiology of abdominal aortic aneurysms

Abdominal aortic aneurysm (AAA) disease remains a major source of morbidity in developed countries and can progress to life-threatening rupture if left untreated, with exceedingly high mortality. The goal of AAA management is to identify and electively repair AAAs before rupture. AAA disease burden and outcomes have improved over time with declining tobacco use and advancements in care across patients' disease course. The introduction of endovascular AAA repair, in particular, has allowed for elective AAA repair in patients previously considered too high risk for open surgery and has contributed to lower rates of AAA rupture over time. However, these improved outcomes are not universally experienced, and disparities continue to exist in the detection, treatment, and outcomes of AAA by sex, race, and ethnicity. Mitigating these disparities requires enhanced, focused efforts at preventing disease, promoting health, and delivering appropriate care among an increasingly diverse patient population.

Status of coronary disease and results from early endovascular aneurysm repair after preventive percutaneous coronary revascularization

BACKGROUND

The incidence of coronary artery disease (CAD) is high in patients with an aortic aneurysm but preoperative routine coronary angiography and preventive coronary revascularization are not recommended to reduce cardiac events in patients with severe CAD.

AIM

This study evaluated the safeness and efficacy of preventive percutaneous coronary intervention (PCI) in patients with severe CAD scheduled for endovascular aneurysm repair (EVAR).

METHODS

All patients with descending thoracic aneurysm (DTA) or abdominal aortic aneurysm (AAA) scheduled for EVAR underwent preliminary coronary angiography. Based on coronary angiography results, 917 patients (40.7%) had significant CAD and were treated by percutaneous coronary intervention (PCI; CAD group) and 1337 patients (59.3%) were without or with mild/moderate CAD and were considered as controls (no-CAD group). To evaluate the safeness and efficacy of preventive PCI in patients with severe CAD undergoing EVAR, groups were compared for hospital and 12-month cardiac adverse events.

RESULTS

CAD was present in 1210 patients (53.6%): significant in 917 patients (38%) and mild to moderate in 293 patients (5.3%). Hospital and 12-month cardiac events occurred in 15 (1.6%) and 13 (1.4%) CAD group patients and in 9 (0.7%) and 8 (0.4%) no-CAD group patients (p = .05 and p = .08), respectively. Hospital and 12-month cardiac deaths occurred in 3 (0.3%) and 2 (0.2%) CAD group patients and in 3 (0.2%) and 2 (0.2%) no-CAD group patients (p = .9 and p = .9), respectively.

CONCLUSION

The strategy to treat severe CAD preoperatively by PCI and early subsequent EVAR brings a similar outcome to that in patients without or with mild/moderate CAD.

Editor's Choice - Mortality is High Following Elective Open Repair of Complex Abdominal Aortic Aneurysms

OBJECTIVE

To evaluate the 30 day mortality of elective open complex abdominal aortic aneurysm (cAAA) repair and identify factors associated with death.

METHODS

This was a retrospective cohort study using a Targeted Vascular Module from the American College of Surgeons National Surgical Quality Improvement Program (NSQIP). All patients undergoing elective repair for juxta- and suprarenal abdominal aortic aneurysm (AAA), or type IV thoraco-abdominal aneurysms (TAAA) from 2011 to 2017 were identified. Thirty day mortality and complication rates for open repair were established. A comparison endovascular aneurysm repair (EVAR) group was extracted from the same time period, and inverse probability weighting was applied for comparison. Logistic regression was used to identify factors independently associated with open repair mortality.

RESULTS

Of the 957 patients who underwent an elective open cAAA repair over the study period, 65 (6.8%) died. The mean age of the patient was 71.3 ± 8.0 years. The distribution by aneurysm type was 605 juxtarenal AAA (28 deaths, 4.6%); 284 suprarenal AAA (16 deaths, 9.5%), and 68 type IV TAAA (10 deaths, 14.7%). During the same time period, there were 1149 endovascular repairs for cAAA, with 43 deaths (3.7%). After inverse probability weighting and weighted logistic regression, open repair 30 day mortality yielded an OR 1.9, 95% CI 1.2-3.1, p = .01 compared with EVAR. Factors independently associated with death included more proximal extent aneurysm (referent [ref]: juxtarenal: OR 2.0 per extent increase, 95% CI 1.4-3.0, p < .001), BMI < 18.5 (OR 4.0, 95% CI 1.6-10.1, p = .003), history of severe chronic obstructive pulmonary disease (COPD) (OR 2.6, 95% CI 1.5-4.4, p = .001), more severe chronic kidney disease (CKD) (ref: none/mild): OR 1.9, 95% CI 1.2-2.8, p = .004), and age (OR 1.06/year, 95% CI 1.02-1.09, p = .002.

CONCLUSION

The 30 day mortality was 4.6% for juxtarenal AAA, 9.5% for suprarenal AAA, and 14.7% for type IV TAAA. The open repair odds of 30 day mortality was nearly twice that of endovascular repair for cAAA. Independent associations with death included BMI <18.5, more severe CKD level, more proximally extending aneurysm, age, and history of advanced COPD.

Psoas muscle area and attenuation are highly predictive of complications and mortality after complex endovascular aortic repair

OBJECTIVE

The present study evaluated the psoas muscle area and attenuation (radiodensity), quantified by computed tomography, together with clinical risk assessment, as predictors of outcomes after fenestrated and branched endovascular aortic repair (FBEVAR).

METHODS

The present single-center study included 504 patients who had undergone elective FBEVAR for pararenal or thoracoabdominal aortic aneurysms. The clinical risk assessment included age, sex, comorbidities, body mass index, glomerular filtration rate, aneurysm size and extent, cardiac stress test results, ejection fraction, and American Society of Anesthesiologists (ASA) score. Preoperative computed tomography was used to measure the psoas muscle area and attenuation at the L3 level. The lean psoas muscle area (LPMA; area in cm² multiplied by attenuation in Hounsfield units [HU]) was calculated by multiplying the area by the attenuation. The risk factors for 90-day mortality, major adverse events (MAEs), and long-term mortality were determined using multivariable analysis. MAEs included 30-day or in-hospital death, acute kidney injury, myocardial infarction, respiratory failure, paraplegia, stroke, and bowel ischemia. A novel risk stratification method was proposed according to the strongest predictors of mortality and MAEs on multivariable analysis.

RESULTS

The 30-day mortality, 90-day mortality, and MAE rates were 2.0%, 5.6%, and 20%, respectively. The independent predictors of 90-day mortality were chronic obstructive pulmonary disease, chronic kidney disease, ASA score, and LPMA. The independent predictors of MAEs were aneurysm diameter, glomerular filtration rate, and LPMA. For long-term mortality, the independent predictors were chronic kidney disease, congestive heart failure, extent I-III thoracoabdominal aortic aneurysms, ASA score, and LPMA. The patients were stratified into three groups according to the ASA score and LPMA: low risk, ASA score II or LPMA >350 cm²HU (n = 290); medium risk, ASA score III and LPMA ≤350 cm²HU (n = 181); and high risk, ASA score IV and LPMA ≤350 cm²HU (n = 33). The 90-day mortality and MAE rates were 1.7% and 16% in the low-, 7.2% and 24% in the medium-, and 30% and 33% in the high-risk patients, respectively (P < .001 and P = .02, respectively). Patients with ASA score IV and LPMA <200 cm²HU, indicating sarcopenia (n = 14) had a 43% risk of death within 90 days. The 3-year survival estimates were 80% ± 3% for the low-, 70% ± 4% for the medium-, and 35% ± 9% for the high-risk patients (P < .001). The mean follow-up time was 3.1 ± 2.3 years.

CONCLUSIONS

LPMA was a strong predictor of outcomes and the only independent predictor of both mortality and MAEs after FBEVAR. A high muscle mass was protective against complications, regardless of the ASA score. Risk stratification based on the ASA score and LPMA can be used to identify patients at excessively high operative risk.

Association and interplay of surgeon and hospital volume with mortality after open abdominal aortic aneurysm repair in the modern era

OBJECTIVE

Operative volume has been used as a marker of quality. Research from previous decades has suggested minimum open abdominal aortic aneurysm (AAA) repair volume requirements for surgeons of 9 to 13 open AAA repairs annually and for hospitals of 18 open AAA repairs annually to purportedly achieve acceptable results. Given concerns regarding the decreased frequency of open repairs in the endovascular era, we examined the association of surgeon and hospital volume with the 30- and 90-day mortality in the Vascular Quality Initiative (VQI) registry.

METHODS

Patients who had undergone elective open AAA repair from 2013 to 2018 were identified in the VQI registry. We performed a cross-sectional evaluation of the association between the average hospital and surgeon volume and 30-day postoperative mortality using a hierarchical Bayesian model. Cross-level interactions were permitted, and random surgeon- and hospital-level intercepts were used to account for clustering. The mortality results were adjusted by standardizing to the observed distribution of relevant covariates in the overall cohort. The outcomes were compared to the Society for Vascular Surgery guidelines recommended criteria of <5% perioperative mortality.

RESULTS

A total of 3078 patients had undergone elective open AAA repair by 520 surgeons at 128 hospitals. The 30- and 90-day risks of postoperative mortality were 4.1% (n = 126) and 5.4% (n = 166), respectively. The mean surgeon volume and hospital volume both correlated inversely with the 30-day mortality. Averaged across all patients and hospitals, we found a 96% probability that surgeons who performed an average of four or more repairs per year achieved <5% 30-day mortality. Substantial interplay was present between surgeon volume and hospital volume. For example, at lower volume hospitals performing an average of five repairs annually, <5% 30-day mortality would be expected 69% of the time for surgeons performing an average of three operations annually. In contrast, at higher volume hospitals performing an average of 40 repairs annually, a <5% 30-day mortality would be expected 96% of the time for surgeons performing an average of three operations annually. As hospital volume increased, a diminishing difference occurred in 30-day mortality between lower and higher volume surgeons. Likewise, as surgeon volume increased, a diminishing difference was found in 30-day mortality between the lower and higher volume hospitals.

CONCLUSIONS

Surgeons and hospitals in the VQI registry achieved mortality outcomes of <5% (Society for Vascular Surgery guidelines), with an average surgeon volume that was substantially lower compared with previous reports. Furthermore, when considering the development of minimal surgeon volume guidelines, it is important to contextualize the outcomes within the hospital volumes.

A comparison of administrative data and quality improvement registries for abdominal aortic aneurysm repair

OBJECTIVE

Databases are essential in evaluating surgical outcomes and gauging the implementation of new techniques. However, there are important differences in how data from administrative databases and surgical quality improvement (QI) registries are collected and interpreted. Therefore, we aimed to compare trends, demographics, and outcomes of open and endovascular abdominal aortic aneurysm (AAA) repair in an administrative database and two QI registries.

METHODS

We identified patients undergoing open and endovascular repair of intact and ruptured AAAs between 2012 and 2015 within the National Inpatient Sample (NIS), the National Surgical Quality Improvement Program (NSQIP), and the Vascular Quality Initiative (VQI). We described the differences and trends in overall AAA repairs for each data set. Moreover, patient demographics, comorbidities, mortality, and complications were compared between the data sets using Pearson χ² test.

RESULTS

A total of 140,240 NIS patients, 10,898 NSQIP patients, and 26,794 VQI patients were included. Ruptured repairs composed 8.7% of NIS, 11% of NSQIP, and 7.9% of VQI. Endovascular aneurysm repair (EVAR) rates for intact repair (range, 83%-84%) and ruptured repair (range, 51%-59%) were similar in the three databases. In general, rates of comorbidities were lower in NIS than in the QI registries. After intact EVAR, in-hospital mortality rates were similar in all three databases (NIS 0.8%, NSQIP 1.0%, and VQI 0.8%; P = .06). However, after intact open repair and ruptured repair, in-hospital mortality was highest in NIS and lowest in VQI (intact open: NIS 5.4%, NSQIP 4.7%, and VQI 3.5% [P < .001]; ruptured EVAR: NIS 24%, NSQIP 20%, and VQI 16% [P < .001]; ruptured open: NIS 36%, NSQIP 31%, and VQI 26% [P < .001]). After stratification by intact and ruptured presentation and repair strategy, several discrepancies in morbidity rates remained between the databases. Overall, the number of cases in NSQIP represents 7% to 8% of the repairs in NIS, and the number of cases in VQI grew from 12% in 2012 to represent 23% of the national sample in 2015.

CONCLUSIONS

NIS had the largest number of patients as it represents the nationwide experience and is an essential tool to evaluate trends over time. The lower in-hospital mortality seen in NSQIP and VQI questions the generalizability of the studies that use these QI registries. However, with a growing number of hospitals engaging in granular QI initiatives, these QI registries provide a valuable resource to potentially improve the quality of care provided to all patients.

Design of the PReferences for Open Versus Endovascular Repair of Abdominal Aortic Aneurysm (PROVE-AAA) Trial

For patients with abdominal aortic aneurysm (AAA), randomized trials have found endovascular AAA repair (EVAR) is associated with lower perioperative morbidity and mortality than open surgical repair (OSR). However, OSR has fewer long-term aneurysm-related complications, such as endoleak or late rupture. Patients treated with EVAR and OSR have similar survival rates within two years after surgery, and OSR does not require intensive surveillance. Few have examined if patient preferences are aligned with the type of treatment they receive for their AAA. Although many assume that patients may universally prefer the less-invasive nature of EVAR, our preliminary work suggests that patients who value the lower risk of late complications may prefer OSR. In this study, called The PReferences for Open Versus Endovascular Repair of Abdominal Aortic Aneurysm (PROVE-AAA) trial, we describe a cluster-randomized trial to test if a decision aid can better align patients' preferences and their treatment type for AAA. Patients enrolled in the study are candidates for either endovascular or open repair and are followed up at VA hospitals by vascular surgery teams who regularly perform both types of repair. In Aim 1, we will determine patients' preferences for endovascular or open repair and identify domains associated with each repair type. In Aim 2, we will assess alignment between patients' preferences and the repair type elected and then compare the impact of a decision aid on this alignment between the intervention and control groups. This study will help us to accomplish two goals. First, we will better understand the factors that affect patient preference when choosing between EVAR and OSR. Second, we will better understand if a decision aid can help patients be more likely to receive the treatment strategy they prefer for their AAA. Study enrollment began on June 1, 2017. Between June 1, 2017 and November 1, 2018, we have enrolled 178 of a total goal of 240 veterans from 20 VA medical centers and their vascular surgery teams across the country. We anticipate completing enrollment in PROVE-AAA in June 2019, and study analyses will be performed thereafter.

Early extubation is associated with reduced length of stay and improved outcomes after elective aortic surgery in the Vascular Quality Initiative

OBJECTIVE

Timing of extubation after open aortic procedures varies across hospitals. This study was designed to examine extubation timing and determine its effect on length of stay (LOS) and respiratory complications after elective open aortic surgery.

METHODS

We studied extubation timing for 7171 patients undergoing elective open abdominal aortic aneurysm repair (2687 [37.5%]) or suprainguinal bypass for aortoiliac occlusive disease (4484 [62.5%]) from October 2010 to April 2015 in hospitals participating in the Vascular Quality Initiative (VQI). Our primary outcome was prolonged LOS (>7 days), and the secondary outcome was respiratory complications (pneumonia or reintubation). The association between extubation timing and outcomes was assessed using multivariable logistic regression mixed-effects models that adjusted for confounding factors at the patient and procedure level. A variable importance analysis was conducted using a chi-pie framework to identify factors contributing to the variability of extubation timing.

RESULTS

The 7171 patients undergoing abdominal aortic surgery were a mean age of 65.4 (standard deviation, 10.2) years, and 63% were male. Extubation occurred (1) in the operating room (76.3%), (2) <12 hours (10.9%), (3) 12 to 24 hours (7.2%), or (4) >24 hours (5.6%) after surgery. Hospitals in the top quartile for case volume had the highest percentage of patients extubated in the operating room (82.8%). Patients least likely to be extubated in the operating room were older, more likely to have chronic obstructive pulmonary disease, require vasopressors, have higher estimated blood loss (EBL), and longer procedure times. After adjustment for patient, procedure, and institutional factors, delayed extubation was associated with prolonged LOS (<12 hours: odds ratio [OR], 1.4; 95% confidence interval [CI], 1.2-1.7; 12-24 hours: OR, 2.1; 95% CI, 1.7-2.7; >24 hours: OR, 5.3; 95% CI, 4.0-6.9), and pulmonary complications (<12 hours: OR, 1.9; 95% CI, 1.4-2.6; 12-24 hours: OR, 2.6; 95% CI, 1.8-3.6; >24 hours: OR, 9.6; 95% CI, 7.1-13.0) compared with those extubated in the operating room. Subset analysis of patients extubated in the operating room or <12 hours showed that extubation out of the operating room was associated with prolonged LOS (OR, 1.4; 95% CI, 1.2-1.7) and pulmonary complications (OR, 1.8; 95% CI, 1.3-2.5). The variable importance analysis demonstrated that EBL (26%) and procedure time (24%) accounted for half of the variation in extubation timing.

CONCLUSIONS

Extubation in the operating room is associated with shorter LOS and morbidity after open aortic surgery. EBL, procedure time, and center variation account for variability in extubation timing. These data advocate for standardized perioperative respiratory care to reduce variation, improve outcomes, and reduce LOS.

Open versus endovascular abdominal aortic aneurysm repair in Medicare beneficiaries

Abdominal aortic aneurysms are relatively common and often life-threatening, with especially high mortality after aneurysm rupture. The introduction of endovascular aneurysm repair, a minimally invasive alternative to traditional open repair, led to decreased mortality and morbidity in randomized controlled trials, but these trials were conducted in highly selected patients and providers and were underpowered to detect differences in rare adverse events throughout follow-up. With observational studies of Medicare beneficiaries, we demonstrate that the randomized trial results are generalizable to the majority of patients undergoing abdominal aortic aneurysm repair in the United States. Additionally, with a larger cohort, comparative analyses evaluating rare, previously unstudied late outcomes such as laparotomy-related complications, late reinterventions, mortality with reinterventions, and late rupture could be conducted. Furthermore, trends in management over time and relationships between surgeon and hospital volume and outcomes can be studied. The goal of this review was to summarize the existing literature regarding abdominal aortic aneurysms among Medicare beneficiaries and to evaluate the benefits and limitations of administrative claims data in comparative effectiveness research.

Worse late-phase survival after elective endovascular than open surgical repair for intact abdominal aortic aneurysm

OBJECTIVES

To determine whether follow-up survival is better after elective endovascular aneurysm repair (EVAR) than open surgical repair (OSR) for intact abdominal aortic aneurysm (AAA), we combined 5-year survival curves themselves of EVAR and OSR in randomized controlled trials (RCTs) and propensity-score matched (PSM) studies.

METHODS

Eligible studies were RCTs or PSM studies of elective EVAR versus OSR enrolling patients with intact AAA and reporting 5-year (at least) survival curves. Data regarding detailed inclusion criteria, duration of follow-up, and survival curves were abstracted from each individual study. In case of crossing of the combined survival curves, a pooled late-phase (between the crossing time and 5years) hazard ratio (HR) for all-cause mortality was calculated.

RESULTS

Our search identified 7 eligible studies (including 2 RCTs and 5 PSM studies) enrolling a total of 92,333 patients with AAA assigned to EVAR or OSR. Pooled survival rates after EVAR and OSR were 98.1% and 96.1 at 1month, 94.2% and 93.1% at 1year, 85.1% and 86.8% at 3years, and 75.8% and 78.8% at 5years, respectively. The survival curves crossed at 1.8years with the survival rate of 90.5%. A pooled late-phase (between 1.8years and 5years) HR for calculated from data of the combined survival curves significantly favored OSR (1.29, 95% confidence interval, 1.24 to 1.35; p<0.00001).

CONCLUSIONS

For intact AAA, although survival was better immediately after elective EVAR than OSR, the survival curves crossed at 1.8years. Thereafter until 5years, survival was worse after EVAR than OSR.

Significant regional variation exists in morbidity and mortality after repair of abdominal aortic aneurysm

OBJECTIVE

Limited data exist comparing perioperative morbidity and mortality after open and endovascular abdominal aortic aneurysm (AAA) repair (EVAR) among regions of the United States. This study evaluated the regional variation in mortality and perioperative outcomes after repair of AAAs.

METHODS

The Vascular Quality Initiative (VQI) was used to identify patients undergoing open AAA repair and EVAR between 2009 and 2014. Ruptured and intact aneurysms were evaluated separately, and the analysis of intact aneurysms was limited to infrarenal AAAs. All 16 regions of the VQI were deidentified, and those with <100 open repairs were combined to eliminate the effect of low-volume regions. Regional variation was evaluated using χ² and Fisher exact tests. Regional rates were compared against current quality benchmarks.

RESULTS

Perioperative outcomes from 14 regions were compared. After open repair of intact aneurysms, no significant variation was seen in 30-day or in-hospital mortality; however, multiple regions exceeded the Society for Vascular Surgery benchmark for in-hospital mortality after open repair of intact aneurysms of <5% (range, 0%-7%; P = .55). After EVAR, all regions met the Society for Vascular Surgery benchmark of <3% (range, 0%-1%; P = .75). Significant variation in in-hospital mortality existed after open (14%-63%; P = .03) and endovascular (3%-32%; P = .03) repair of ruptured aneurysms across the VQI regional groups. After repair of intact aneurysms, wide variation was seen in prolonged length of stay (>7 days for open repair: 32%-53%, P = .54; >2 days for EVAR: 16-43%, P < .01), transfusion (open: 10%-35%, P < .01; EVAR: 7%-18%, P < .01), use of vasopressors (open: 19%-37%, P < .01; EVAR: 3%-7%, P < .01), and postoperative myocardial infarction (open: 0%-13%, P < .01; EVAR: 0%-3%, P < .01). After open repair, worsening renal function (6%-18%; P = .04) and respiratory complications (6%-20%; P = .20) were variable across regions. The frequency of endoleak at completion of EVAR also had considerable variation (15%-38%; P < .01).

CONCLUSIONS

Despite limited variation, multiple regions do not meet current benchmarks for in-hospital mortality after open AAA repair for intact aneurysms. Significant regional variation exists in perioperative outcomes and length of stay, and mortality is widely variable after repair for rupture. These data identify important areas for quality improvement initiatives and clinical practice guidelines.

Patient selection and perioperative outcomes are similar between targeted and nontargeted hospitals (in the National Surgical Quality Improvement Program) for abdominal aortic aneurysm repair

OBJECTIVE

The targeted vascular module in the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) consists of self-selected hospitals that choose to collect extra clinical details for better risk adjustment and improved procedure-specific outcomes. The purpose of this study was to compare patient selection and outcomes between targeted and nontargeted hospitals in the NSQIP regarding the operative management of abdominal aortic aneurysm (AAA).

METHODS

We identified all patients who underwent endovascular aneurysm repair (EVAR) or open AAA repair from 2011 to 2013 and compared cases by whether the operation took place in a targeted or nontargeted hospital. EVAR and open repair as well as intact and ruptured aneurysms were evaluated separately. Only variables contained in both modules were used to evaluate rupture status and operation type. All thoracoabdominal aneurysms were excluded. Univariate analysis was performed for intact and ruptured EVAR and open repair grouped by complexity, defined as visceral involvement in open repair and a compilation of concomitant procedures for EVAR. Multivariable models were developed to identify effect of hospital type on mortality.

RESULTS

There were 17,651 AAA repairs identified. After exclusion of aneurysms involving the thoracic aorta (n = 352), there were 1600 open AAA repairs at targeted hospitals (21% ruptured) and 2725 at nontargeted hospitals (19% ruptured) and 4986 EVARs performed at targeted hospitals (6.7% ruptured) and 7988 at nontargeted hospitals (5.2% ruptured). There was no significant difference in 30-day mortality rates between targeted and nontargeted hospitals for intact aneurysms (EVAR noncomplex, 1.8% vs 1.4% [P = .07]; open repair noncomplex, 4.2% vs 4.5% [P = .7]; EVAR complex, 5.0% vs 3.2% [P = .3]; open repair complex, 8.0% vs 6.0% [P = .2]). For ruptured aneurysms, again there was no difference in mortality between the targeted and nontargeted hospitals (EVAR noncomplex, 23% vs 25% [P = .4]; open repair noncomplex, 38% vs 34% [P = .2]; EVAR complex, 29% vs 33% [P = 1.0]; open repair complex, 27% vs 41% [P = .09]). Multivariable analysis further demonstrated that having an operation at a targeted vs nontargeted hospital had no impact on mortality for both intact and ruptured aneurysms (odds ratio, 1.1 [0.9-1.4] and 1.0 [0.8-1.3], respectively).

CONCLUSIONS

This analysis highlights the similarities between targeted and nontargeted hospitals within the NSQIP for AAA operative management and suggests that data from the targeted NSQIP, in terms of AAA management, are generalizable to all NSQIP hospitals.

Long-Term Outcomes of Abdominal Aortic Aneurysm in the Medicare Population

BACKGROUND

Randomized trials and observational studies have shown that perioperative morbidity and mortality are lower with endovascular repair of abdominal aortic aneurysm than with open repair, but the survival benefit is not sustained. In addition, concerns have been raised about the long-term risk of aneurysm rupture or the need for reintervention after endovascular repair.

METHODS

We assessed perioperative and long-term survival, reinterventions, and complications after endovascular repair as compared with open repair of abdominal aortic aneurysm in propensity-score-matched cohorts of Medicare beneficiaries who underwent repair during the period from 2001 through 2008 and were followed through 2009.

RESULTS

We identified 39,966 matched pairs of patients who had undergone either open repair or endovascular repair. The overall perioperative mortality was 1.6% with endovascular repair versus 5.2% with open repair (P<0.001). From 2001 through 2008, perioperative mortality decreased by 0.8 percentage points among patients who underwent endovascular repair (P=0.001) and by 0.6 percentage points among patients who underwent open repair (P=0.01). The rate of conversion from endovascular to open repair decreased from 2.2% in 2001 to 0.3% in 2008 (P<0.001). The rate of survival was significantly higher after endovascular repair than after open repair through the first 3 years of follow-up, after which time the rates of survival were similar. Through 8 years of follow-up, interventions related to the management of the aneurysm or its complications were more common after endovascular repair, whereas interventions for complications related to laparotomy were more common after open repair. Aneurysm rupture occurred in 5.4% of patients after endovascular repair versus 1.4% of patients after open repair through 8 years of follow-up (P<0.001). The rate of total reinterventions at 2 years after endovascular repair decreased over time (from 10.4% among patients who underwent procedures in 2001 to 9.1% among patients who underwent procedures in 2007).

CONCLUSIONS

Endovascular repair, as compared with open repair, of abdominal aortic aneurysm was associated with a substantial early survival advantage that gradually decreased over time. The rate of late rupture was significantly higher after endovascular repair than after open repair. The outcomes of endovascular repair have been improving over time. (Funded by the National Institutes of Health.).

Misdiagnosis of ruptured abdominal aortic aneurysm: systematic review and meta-analysis

PURPOSE

To quantitatively summarize the incidence of misdiagnosis of ruptured abdominal aortic aneurysms (rAAA), the most common presenting features, and the commonest incorrect differential diagnoses.

METHODS

A systematic search according to PRISMA guidelines was performed using EMBASE and MEDLINE databases to identify studies reporting the initial rate of misdiagnosis of patients with rAAA. Random-effects meta-analyses were performed to estimate the rate of misdiagnosis, presenting features, and commonest differential diagnoses. A sensitivity analysis was performed for studies reporting after 1990.

RESULTS

Nine studies comprising 1109 patients contributed to the pooled analysis, which found a 42% incidence of rAAA misdiagnosis (95% CI 29% to 55%). In studies reporting after 1990, misdiagnosis was seen in 32% (95% CI 16% to 49%). The most common erroneous differential diagnoses were ureteric colic and myocardial infarction. Abdominal pain, shock, and a pulsatile mass were presenting features in 61% (49%-72%), 46% (32%-61%), and 45% (29%-62%) of rAAAs, respectively.

CONCLUSION

The rate of misdiagnosis of rAAA has remained consistent over time and is concerning. There is a need for an effective clinical decision tool to enable accurate diagnosis and triage at the scene of the emergency.

National trends in incidence and outcomes of abdominal aortic aneurysm among elderly type 2 diabetic and non-diabetic patients in Spain (2003-2012)

BACKGROUND

This study aims to describe trends in the rate of abdominal aortic aneurysm (AAA) and use of open surgery repair (OSR) and endovascular aneurysm repair (EVAR) in elderly patients with and without type 2 diabetes in Spain, 2003-2012.

METHODS

We select all patients with a discharge of AAA using national hospital discharge data. Discharges were grouped by diabetes status: type 2 diabetes and no diabetes. In both groups OSR and EVAR were identified. The incidence of discharges attributed to AAA were calculated overall and stratified by diabetes status and year. We calculated length of stay (LOHS) and in-hospital mortality (IHM). Use of OSR and EVAR were calculated stratified by diabetes status. Multivariate analysis was adjusted by age, sex, year, smoking habit and comorbidity.

RESULTS

From 2003 to 2012, 115,020 discharges with AAA were identified. The mean age was 74.91 years and 16.7% suffered type 2 diabetes. Rates of discharges due to AAA increased significantly in diabetic patients (50.09 in 2003 to 78.23 cases per 100,000 in 2012) and non diabetic subjects (69.24 to 78.66). The incidences were higher among those without than those with diabetes in all the years studied. The proportion of patients that underwent EVAR increased for both groups of patients and the open repair decreased. After multivariate analysis we found that LOHS and IHM have improved over the study period and diabetic patients had lower IHM than those without diabetes (OR 0.81; 95%CI 0.76-0.85).

CONCLUSIONS

Incidence rates were higher in non-diabetic patients. For diabetic and non diabetic patients the use of EVAR has increased and open repair seems to be decreasing. IHM and LOHS have improved from 2003 to 2012. Patients with diabetes had significantly lower mortality.

The effect of endovascular treatment on isolated iliac artery aneurysm treatment and mortality

OBJECTIVE

Isolated iliac artery aneurysms are rare, but potentially fatal. The effect of recent trends in the use of endovascular iliac aneurysm repair (EVIR) on isolated iliac artery aneurysm-associated mortality is unknown.

METHODS

We identified all patients with a primary diagnosis of iliac artery aneurysm in the National Inpatient Sample from 1988 to 2011. We examined trends in management (open vs EVIR, elective and urgent) and overall isolated iliac artery aneurysm-related deaths (with or without repair). We compared in-hospital mortality and complications for the subgroup of patients undergoing elective open and EVIR from 2000 to 2011.

RESULTS

We identified 33,161 patients undergoing isolated iliac artery aneurysm repair from 1988 to 2011, of which there were 9016 EVIR and 4933 open elective repairs from 2000 to 2011. Total repairs increased after the introduction of EVIR, from 28 to 71 per 10 million United States (U.S.) population (P < .001). EVIR surpassed open repair in 2003. Total isolated iliac artery aneurysm-related deaths, due to rupture or elective repair, decreased after the introduction of EVIR from 4.4 to 2.3 per 10 million U.S. population (P < .001). However, urgent admissions did not decrease during this time period (15 to 15 procedures per 10 million U.S. population; P = .30). Among elective repairs after 2000, EVIR patients were older (72.4 vs 69.4 years; P = .002) and were more likely to have a history of prior myocardial infarction (14.0% vs 11.3%; P < .001) and renal failure (7.2% vs 3.6%; P < .001). Open repair had significantly higher rate of in-hospital mortality (1.8% vs 0.5%; P < .001) and complications (17.9% vs 6.7%; P < .001) and a longer length of stay (6.7 vs 2.3 days; P < .001).

CONCLUSIONS

Treatment of isolated iliac artery aneurysms has increased since the introduction of EVIR and is associated with lower perioperative mortality, despite a higher burden of comorbid illness. Decreasing iliac artery aneurysm-attributable in-hospital deaths are likely related primarily to lower elective mortality with EVIR rather than rupture prevention.

Clinical outcome of an extended proximal seal zone with the AFX endovascular aortic aneurysm system

OBJECTIVE

Despite improvements in endograft technology, operator skill, and patient selection, endovascular aneurysm repair continues to be associated with device-related complications. A retrospective, observational study was undertaken to evaluate the clinical outcome and imaging findings of a unique device having externally-mounted, conformable graft material.

METHODS

Infrarenal abdominal aortic aneurysms were treated with the Endologix, Inc AFX endovascular aortic aneurysm system (Irvine, Calif) endograft in 108 consecutive patients over a 25-month period at two U.S. clinical sites. Baseline characteristics and procedural outcomes were reviewed by independent monitors. Serial computed tomography (CT) imaging assessments were performed by an independent core laboratory. Aortic neck characteristics and graft apposition were analyzed from center line-reformatted CT data sets in 37 patients in an imaging cohort comprising subjects with high-resolution baseline and follow-up CT imaging for precise assessment of aortic neck characteristics. The mean follow-up was 11 ± 5 months overall, 9 ± 6 months in patients with core laboratory imaging, and 5 ± 2 months for patients in the imaging cohort.

RESULTS

Among the 108 patients, 103 (95%) had intact aneurysms and five (4.6%) were treated for rupture; 80 (74%) were male and 28 (26%) were female. On average, 2.3 ± 0.7 endograft components were implanted per patient and no adjunctive proximal neck bare stents were used. There were no perioperative deaths in patients with intact aneurysms; two patients who presented with ruptured aortic aneurysms (40%) died. Major adverse events occurred within 30 days of implantation in two patients (1.9%) with intact aneurysms. Type II endoleaks were evident on completion angiography in 18 patients (16.7%). Core laboratory analysis of CT studies identified two patients with type Ia endoleaks (2.3%), two with type III endoleaks (2.3%), and five with type II endoleaks (5.7%). Aneurysm-related secondary procedures were required in five patients over the first year of follow-up (4.6%). No patient developed endograft limb occlusion or aneurysm rupture and there were no open surgical conversions. In the imaging cohort, 360° graft-to-aortic wall apposition was continuous over a length of 25 ± 17 mm and extended the seal zone an average of 5 mm beyond the end of the anatomic neck. Early sac regression was correlated with neck length (P = .019) and graft-to-aortic apposition surface area (P = .039).

CONCLUSIONS

The real-world use of the AFX endograft was associated with a low rate of device-and procedure-related complications. The ability to achieve an extended seal zone beyond the anatomical neck might in part contribute to positive outcomes, including the low type Ia and type II endoleak rate. These findings suggest that the AFX device might offer some advantages over other currently marketed endografts, but confirmation awaits the availability of longer-term outcome data.

Hospitalization rates and post-operative mortality for abdominal aortic aneurysm in Italy over the period 2000-2011

Background

Recent studies have reported declines in incidence, prevalence and mortality for abdominal aortic aneurysms (AAAs) in various countries, but evidence from Mediterranean countries is lacking. The aim of this study is to examine the trend of hospitalization and post-operative mortality rates for AAAs in Italy during the period 2000–2011, taking into account the introduction of endovascular aneurysm repair (EVAR) in 1990s.

Methods

This retrospective cohort study was carried out in Emilia-Romagna, an Italian region with 4.5 million inhabitants. A total of 19,673 patients hospitalized for AAAs between 2000 and 2011, were identified from the hospital discharge records (HDR) database. Hospitalization rates, percentage of OSR and EVAR and 30-day mortality rates were calculated for unruptured (uAAAs) and ruptured AAAs (rAAAs).

Results

Adjusted hospitalization rates decreased on average by 2.9% per year for uAAAs and 3.2% for rAAAs (p<0.001). The temporal trend of 30-day mortality rates remained stable for both groups. The percentage of EVAR for uAAAs increased significantly from 2006 to 2011 (42.7 versus 60.9% respectively, mean change of 3.9% per year, p<0.001). No significant difference in mortality was found between OSR and EVAR for uAAAs and rAAAs.

Conclusions

The incidence and trend of hospitalization rates for rAAAs and uAAAs decreased significantly in the last decade, while 30-day mortality rates in operated patients remained stable. OSR continued to be the most common surgery in rAAAs, although the gap between OSR and EVAR recently declined. The EVAR technique became the preferred surgery for uAAAs since 2008.

Abdominal aortic aneurysms: endovascular options and outcomes - proliferating therapy, but effective?

Abdominal aortic aneurysm (AAA) has a reported prevalence rate of 1.4% in the US. AAA rupture accounts for an estimated 15,000 deaths per year, rendering it the 10th leading cause of death in men over the age of 55. Endovascular repair (EVR) has proliferated in the last two decades as an increasingly popular alternative to traditional open surgery, and is now the default treatment in the majority of centres worldwide. This review article outlines the evidence supporting this stance. The development of EVR is reviewed, alongside trends in utilisation of this therapy over time. The evidence for the relative short-term and long-term outcomes of EVR and open AAA repair is discussed, and ongoing controversies surrounding the use of EVR are considered.

Specialized vascular floors after open aortic surgery: cost containment while preserving quality outcomes

BACKGROUND

Postoperative care of open abdominal aortic surgery (OAAS) traditionally involves the intensive care unit (ICU). We hypothesized that in patients without an indication for postoperative ICU admission, admission to a specialized vascular floor unit (hemodynamic monitoring, 2:1 nursing) offers cost savings to both payer and institution without compromising care.

METHODS

The electronic medical record was used to collect perioperative data for patients who underwent OAAS between July 2007 and July 2011. The university's cost accounting system provided information on revenue, total margin, and professional billing. Patients with ICU indications (spinal drain, Swan-Ganz monitoring, vasopressors, intubation, or blood product resuscitation) were excluded. Comparative cost and outcome analysis was performed on vascular ward and ICU admissions using the Fisher's exact test for dichotomous categorical variables and the Student's t-test for continuous variables. Long-term survival comparison was calculated using Kaplan-Meier survival estimates.

RESULTS

One hundred thirty of 215 patients were included for analysis (85 excluded, 51 floor, 79 ICU). Perioperative data amongst the floor and ICU cohorts were similar. Day of operation professional billing fees were comparable (ICU $13,365 vs. floor $12,626; P = 0.18); however, postoperative professional fees were significantly higher in the ICU cohort (ICU $3,258 vs. floor $2,101; P = 0.001) primarily because of intensivist billing. The hospital generated an average of 8.7% more revenue from the ICU cohort (ICU $37,770 vs. floor $34,756; P = 0.023). This was offset by greater expenses in the ICU cohort (ICU $30,756 vs. floor $25,144; P = 0.02), yielding a hospital profit margin of 107.5% favoring floor admission (ICU $2,858 vs. floor $5,931; P = 0.19). Duration of stay was similar (ICU 8.0 days vs. floor 7.8 days; P = 0.86). Kaplan-Meier survival analysis was not significantly different between cohorts (ICU 10.1%, median follow-up, 1,070 days vs. floor 0%, median follow-up, 405 days; P = 0.13).

CONCLUSIONS

Postoperative admission to the ICU is not always necessary after OAAS. Specialized vascular floors offer a financial savings to both payer and institution, which allows for simultaneous cost containment while preserving quality outcomes.

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

STUDY OBJECTIVE

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

DESIGN

Retrospective analysis of a prospective cohort.

SETTINGS

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

MEASUREMENTS

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

MAIN RESULTS

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

CONCLUSIONS

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

Ten-year results of endovascular abdominal aortic aneurysm repair from a large multicenter registry

OBJECTIVE

To assess outcomes after endovascular abdominal aortic aneurysm repair (EVAR) in an integrated health care system.

METHODS

Between 2000 and 2010, 1736 patients underwent EVAR at 17 centers. Demographic data, comorbidities, and outcomes of interest were collected. EVAR in patients presenting with ruptured or symptomatic aneurysms was categorized as urgent; otherwise, it was considered elective. Primary outcomes were mortality and aneurysm-related mortality (ARM). Secondary outcomes were change in aneurysm sac size, endoleak status, major adverse events, and reintervention.

RESULTS

Overall, the median age was 76 years (interquartile range, 70-81 years), 86% were male, and 82% were Caucasian. Most cases (93.8%) were elective, but urgent use of EVAR increased from 4% in the first 5 years to 7.3% in the last 5 years of the study period. Mean aneurysm size was 5.8 cm. Patients were followed for an average of 3 years (range, 1-11 years); 8% were lost to follow-up. Intraoperatively, 4.5% of patients required adjunctive maneuvers for endoleak, fixation, or flow-limiting issues. The 30-day mortality rate was 1.2%, and the perioperative morbidity rate was 6.6%. Intraoperative type I and II endoleaks were uncommon (2.3% and 9.3%, respectively). Life-table analysis at 5 years demonstrated excellent overall survival (66%) and freedom from ARM (97%). Postoperative endoleak was seen in 30% of patients and was associated with an increase in sac size over time. Finally, the total reintervention rate was 15%, including 91 instances (5%) of revisional EVAR. The overall major adverse event rate was 7.9% and decreased significantly from 12.3% in the first 5 years to 5.6% in the second 5 years of the study period (P < .001). Overall ARM was worse in patients with postoperative endoleak (4.1% vs 1.8%; P < .01) or in those who underwent reintervention (7.6% vs 1.6%; P < .001).

CONCLUSIONS

Results from a contemporary EVAR registry in an integrated health care system demonstrate favorable perioperative outcomes and excellent clinical efficacy. However, postoperative endoleak and the need for reintervention continue to be challenging problems for patients after EVAR.

Development of a risk index for prediction of mortality after open aortic aneurysm repair

OBJECTIVE

Open infrarenal abdominal aortic aneurysm (oAAA) repair is associated with significant morbidity and mortality. Although there has been a shift toward endovascular repair, many patients continue to undergo an open repair due to anatomic considerations. Tools currently existing for estimation of periprocedural risk in patients undergoing open aortic surgery have certain limitations. The objective of this study was to develop a risk index to estimate the risk of 30-day perioperative mortality after elective oAAA repair.

METHODS

Patients who underwent elective oAAA repair (n = 2845) were identified from the American College of Surgeons' 2007 to 2009 National Surgical Quality Improvement Program (NSQIP), a prospective database maintained at >250 centers. Univariable and multivariable analyses were performed to evaluate risk factors associated with 30-day mortality after oAAA repair and a risk index was developed.

RESULTS

The 30-day mortality after oAAA repair was 3.3%. Multivariable analysis identified six preoperative predictors of mortality, and a risk index was created by assigning weighted points to each predictor using the β-coefficients from the regression analysis. The predictors included dyspnea (at rest: 8 points; on moderate exertion: 2 points; none: 0 points), history of peripheral arterial disease requiring revascularization or amputation (3 points), age >65 years (3 points), preoperative creatinine >1.5 mg/dL (2 points), female gender (2 points), and platelets <150,000/mm(3) or >350,000/mm(3) (2 points). Patients were classified as low (<7%), intermediate (7%-15%), and high (>15%) risk for 30-day mortality based on a total point score of <8, 8 to 11, and >11, respectively. There were 2508 patients (88.2%) patients in the low-risk category, 278 (9.8%) in the intermediate-risk category, and 59 (2.1%) in the high-risk category.

CONCLUSIONS

This risk index has excellent predictive ability for mortality after oAAA repair and awaits validation in subsequent studies. It is anticipated to aid patients and surgeons in informed patient consent, preoperative risk assessment, and optimization.

Clinical indicators in surgery: a critical review of the Australian experience

BACKGROUND

A set of clinical measures (indicators), developed by an Australian Council on Healthcare Standards (ACHS) and Royal Australasian College of Surgeons (RACS) working party, was introduced into the accreditation programme in 1997. Although early qualitative and quantitative reporting by health-care organizations (HCOs) reflected their value in stimulating change, the number of HCOs reporting data on this set of clinical indicators (CIs) has declined, despite an increase in the number of HCOs reporting data on the CIs programme overall. Possible reasons for this decline were sought.

METHODS

A retrospective review of prospectively collected surgical CI data was performed, a national survey of stakeholders in the ACHS programme was conducted and a comparison was made with published international data.

RESULTS

From a maximum of 247 HCOs reporting data in 2002, the number fell to 168 by 2011. While favourable trends were evident with some CIs, for example, a decline in the rate of negative histology in childhood appendicectomy and in the rate of in-hospital infection in total hip joint replacement, there was minimal change with many of the CIs, suggesting limited responsiveness as measures of care. In the national survey, stakeholder's response was positive overall, but there was a requirement for regular review of CIs. Although some colleges viewed the CIs as simplistic and not reliable, comparisons with similar measures available in the international literature were favourable.

CONCLUSIONS

Possible reasons for the declining number of HCOs reporting surgical CI data are a lack of a recent revision of the CIs and a lack of engagement of clinicians from the RACS. Revision of the surgical CI set is required.

Standardization of outcome measures in clinical trials of pharmacological treatment for abdominal aortic aneurysm

An abdominal aortic aneurysm (AAA) is a common aortic wall disease with an increased prevalence in the elderly population (4-8% for those aged >65 years). Many AAAs are slow growing and remain insidious. Current standard of care for patients with small AAAs (<49 mm) is surveillance, with interventional therapy (open surgical repair or endovascular aneurysm repair) recommended for large (>50-55 mm), rapidly growing (>10 mm/year) or symptomatic AAAs. Although open surgical repair or endovascular aneurysm repair are effective, significant short- and long-term postoperative morbidity and mortality occurs. Currently, there is no pharmacological treatment specific for AAA; the need for the development of targeted pharmacological therapies based on clinically relevant and feasible outcomes acceptable to the medical community, regulatory agencies and third-party payers is high. A consensus on such end points will be critical to accelerating the development of pharmacological agents to prevent formation, arrest the expansion and reduce the rupture risk of AAA.

Predictive factors for mortality after open repair of paravisceral abdominal aortic aneurysm

OBJECTIVE

The use of fenestrated and branched stent graft technology for paravisceral abdominal aortic aneurysms (PAAA) is on the rise; however, its application is limited in the United States to only a few selected centers. Most PAAAs are currently repaired using an open approach. The objective of this study was to determine which patients are at highest risk with open PAAA repair and might benefit most from endovascular repair using fenestrated or branched stent grafts.

METHODS

This was a retrospective cohort study using data from American College of Surgeons National Surgical Quality Improvement Program (NSQIP) hospitals. We identified 598 patients (27.5% women) who underwent elective open PAAA repair from the 2007 to 2009 NSQIP, a prospective database maintained at >250 centers. The main outcome measure was 30-day postoperative mortality.

RESULTS

The median patient age was 73 years. The 30-day major morbidity rate was 30.1%, and the mortality rate was 4.5%. Major complications included reintubation (10.0%), sepsis (10.7%), return to operating room (9.2%), new dialysis requirement (5.9%), cardiac arrest or myocardial infarction (4.5%), and stroke (1.2%). Multivariate analyses identified four predictors of postoperative mortality after open PAAA repair: peripheral arterial disease (PAD) requiring revascularization or amputation, chronic obstructive pulmonary disease (COPD), anesthesia time, and female sex. PAD and COPD were present in only 5.2% and 20.4% of patients but were associated with a 16.1% and 9.0% mortality rate, respectively. The mortality rate in women was 7.3% vs 3.5% for men (P = .045).

CONCLUSIONS

PAD, COPD, and female sex are major risk factors for postoperative mortality after open PAAA repair. Fenestrated or branched stent graft repair may be a more valuable alternative to open repair for patients with one or more of these characteristics who have suitable access vessels.