Robustness of Longitudinal Safety and Efficacy After Paclitaxel-Based Endovascular Therapy for Treatment of Femoro-Popliteal Artery Occlusive Disease: An Updated Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

The aims of this study were: i) to assess fragility indices (FIs) of individual randomized controlled trials (RCTs) that compared paclitaxel-based drug-coated balloons (DCBs) or drug-eluting stents (DESs) versus standard endovascular devices, and ii) to meta-analyze mid-term and long-term safety and efficacy outcomes from available RCT data while also estimating the FI of pooled results.

METHODS

This systematic review has been registered in the PROSPERO public database (CRD42022304326 http://www.crd.york.ac.uk/PROSPERO). A query of PubMed (Medline), EMBASE (Excerpta Medical Database), Scopus, and CENTRAL (Cochrane Central Register of Controlled Trials) databases was performed to identify eligible RCTs. Rates of primary patency (PP) and target lesion revascularization (TLR) were assessed as efficacy outcomes, while lower limb amputation (LLA) consisting of major amputation that is. below or above the knee and all-cause mortality were estimated as safety outcomes. All outcomes were pooled with a random effects model to account for any clinical and study design heterogeneity. The analyses were performed by dividing the RCTs according to their maximal follow-up length (mid-term was defined as results up to 2-3 years, while long-term was defined as results up to 4-5 years). For each individual outcome, the FI and reverse fragility index (RFI) were calculated according to whether the outcome results were statistically significant or not, respectively. The fragility quotient (FQ) and reverse fragility quotient (RFQ), which are the FI or RFI divided by the sample size, were also calculated.

RESULTS

A total of 2,337 patients were included in the systematic review and meta-analysis. There were 2 RCTs examining DES devices and 14 RCTs evaluating different DCBs. For efficacy outcomes, there was evidence that paclitaxel-based endovascular therapy increased the PP rate and reduced the TLR rate at mid-term, with a calculated pooled risk ratio (RR) of 1.66 for patency (95% CI, 1.55-1.86; P < 0.001), with a corresponding number needed-to-treat (NNT) of 3 patients (95% CI, 2.9-3.8) and RR of 0.44 for TLR (95% CI, 0.35-0.54; P = 0.027), respectively. Similarly, there was evidence that paclitaxel-based endovascular therapy both increased PP and decreased TLR rates at long-term, with calculated pooled RR values of 1.73 (95% CI, 1.12-2.61; P = 0.004) and 0.53 (95% CI, 0.45-0.62; P = 0.82), respectively. For safety outcomes, there was evidence that paclitaxel-based endovascular therapy increased all-cause mortality at mid-term, with a calculated pooled RR of 2.05 (95% CI, 1.21-3.24). However, there was no difference between treatment arms in LLA at mid-term (95% CI, 0.1-2.7; P = 0.68). Similarly, neither all-cause mortality nor LLA at long-term differed between treatment arms, with a calculated pooled RR of 0.66, 1.02 (95% CI, 0.31-3.42) and 1.02 (95% CI, 0.30-5.21; P = 0.22), respectively. The pooled estimates of PP at mid-term were robust (FI = 28 and FQ = 1.9%) as were pooled rates of TLR (FI = 18 and FQ = 0.9%). However, when safety outcomes were analyzed, the robustness of the meta-analysis decreased significantly. In fact, the relationship between the use of paclitaxel-coated devices and all-cause mortality at mid-term showed very low robustness (FI = 4 and FQ = 0.2%). At 5 years, only the benefit of paclitaxel-based devices to reduce TLR remained robust, with an FI of 32 and an FQ of 3.1%.

CONCLUSIONS

The data supporting clinical efficacy endpoints of RCTs that examined paclitaxel-based devices in the treatment of femoral-popliteal arterial occlusive disease were robust; however, the pooled safety endpoints were highly fragile and prone to bias due to loss of patient follow-up in the original studies. These findings should be considered in the ongoing debate concerning the safety of paclitaxel-based devices.

Long-term costs to Medicare associated with endovascular and open repairs of infrarenal and complex abdominal aortic aneurysms

OBJECTIVE

The vast majority of patients with abdominal aortic aneurysms (AAAs) undergoing repairs receive endovascular interventions (EVARs) instead of open operations (OARs). Although EVARs have better short-term outcomes, OARs have improved longer-term durability and require less radiographic follow-up and monitoring, which may have significant implications on health care economics surrounding provision of AAA care nationally. Herein, we compared costs associated with EVAR and OAR of both infrarenal and complex AAAs.

METHODS

We examined patients undergoing index elective EVARs or OARs of infrarenal and complex AAAs in the 2014-2019 Vascular Quality Initiative-Vascular Implant Surveillance and Interventional Outcomes Network (VQI-VISION) dataset. We defined overall costs as the aggregated longitudinal costs associated with: (1) the index surgery; (2) reinterventions; and (3) imaging tests. We evaluated overall costs up to 5 years after infrarenal AAA repair and 3 years for complex AAA repair. Multivariable regressions adjusted for case-mix when evaluating cost differences between EVARs vs OARs.

RESULTS

We identified 23,746 infrarenal AAA repairs (8.7% OAR, 91% EVAR) and 2279 complex AAA repairs (69% OAR, 31% EVAR). In both cohorts, patients undergoing EVARs were more likely to be older and have more comorbidities. The cost for the index procedure for EVARs relative to OARs was lower for infrarenal AAAs ($32,440 vs $37,488; P < .01) but higher among complex AAAs ($48,870 vs $44,530; P < .01). EVARs had higher annual imaging and reintervention costs during each of the 5 postoperative years for infrarenal aneurysms and the 3 postoperative years for complex aneurysms. Among patients undergoing infrarenal AAA repairs who survived 5 years, the total 5-year cost of EVARs was similar to that of OARs ($35,858 vs $34,212; -$223 [95% confidence interval (CI), -$3042 to $2596]). For complex AAA repairs, the total cost at 3 years of EVARs was greater than OARs ($64,492 vs $42,212; +$9860 [95% CI, $5835-$13,885]). For patients receiving EVARs for complex aneurysms, physician-modified endovascular grafts had higher index procedure costs ($55,835 vs $47,064; P < .01) although similar total costs on adjusted analyses (+$1856 [95% CI, -$7997 to $11,710]; P = .70) relative to Zenith fenestrated endovascular grafts among those that were alive at 3 years.

CONCLUSIONS

Longer-term costs associated with EVARs are lower for infrarenal AAAs but higher for complex AAAs relative to OARs, driven by reintervention and imaging costs. Further analyses to characterize the financial viability of EVARs for both infrarenal and complex AAAs should evaluate hospital margins and anticipated changes in costs of devices.

Conflicting European and North American Society Abdominal Aortic Aneurysm (AAA) Volume Guidelines Differentially Discriminate Peri-operative Mortality After Elective Open AAA Repair

OBJECTIVE

The European Society for Vascular Surgery (ESVS) guidelines endorse a minimum abdominal aortic aneurysm (AAA) repair volume of 20 open (OAR) and or endovascular (EVAR) AAA repair procedures per year as a proxy for high quality care. In contrast, the Society for Vascular Surgery (SVS) espouses 10 exclusively OARs per year. Given the differences in these volume standards and definitions, debate persists regarding surgeon credentialing and healthcare resource allocation. This analysis aimed to determine which society endorsed volume benchmark better discriminates OAR mortality.

METHODS

A retrospective national registry based cohort analysis. Patients undergoing elective OAR were compared between centres meeting either ESVS (≥ 20 AAA procedures/year) or SVS (≥ 10 OARs/year) volume thresholds within the Vascular Quality Initiative (2010 - 2020). The primary outcome was in hospital death. Logistic regression was used for risk adjusted comparisons.

RESULTS

A total of 8 761 OARs were performed at 193 US centres, and the median (IQR) volume was 6.6 (3.3, 9.9) OARs/year. When applying the SVS centre volume definition, the proportion of centres meeting ESVS and SVS minimum case thresholds was 12% (n = 22) and 25% (n = 48), respectively. The absolute mortality difference was 0.3% between centres performing ≥ 20 vs. ≥ 10 OARs/year (2.6% vs. 2.9%; p = .51). There was an incremental association between OAR volume and crude mortality rate; however, this absolute difference between lower and higher thresholds was only 0.2%/procedure (OR 0.98, 95% CI 0.97 - 0.99; p < .001). Moreover, no difference in risk adjusted mortality was detected between volume standards (≥ 10 vs. ≥ 20; p = .78). In sub-analysis, the ESVS ≥ 20 total composite AAA repair volume threshold was not associated with mortality (p = .17); however, increasing the proportion of OAR cases making up the total annual AAA centre volume inversely correlated with mortality (p = .008).

CONCLUSION

It appears that the SVS endorsed AAA centre volume threshold using exclusively OAR had a modest ability to discriminate peri-operative mortality outcomes and was superior to the current composite ESVS volume guideline in differentiating centre performance. These findings raise questions regarding the clinical validity of using EVAR as a volume proxy for OAR.

Long-term Mortality and Reintervention After Repair of Ruptured Abdominal Aortic Aneurysms Using VQI-matched Medicare Claims

OBJECTIVE

The objective of this study was to compare endovascular aortic aneurysm repair (EVAR) versus open aortic repair (OAR) on mortality and reintervention after ruptured infrarenal abdominal aortic aneurysm (rAAA) repair in the Vascular Quality Initiative (VQI).

BACKGROUND

The optimal treatment modality for rAAA remains debated, with little data on long-term comparisons.

METHODS

VQI rAAA repairs (2004-2018) were matched with Medicare claims (VQI-VISION). Primary outcomes were in-hospital and long-term mortality. Secondary outcome was reintervention. Inverse probability weighting was used to adjust for treatment selection, and Cox Proportional Hazards models and negative binomial regressions were used for analysis. Landmark analysis was performed among patients surviving hospital discharge.

RESULTS

Among 1885 VQI/Medicare rAAA patients, 790 underwent OAR, and 1095 underwent EVAR. Median age was 76 years; 73% were male. Inverse probability weighting produced comparable groups. In-hospital mortality was lower after EVAR versus OAR (21% vs 37%, odds ratio: 0.52, 95% CI, 0.4-0.7). One-year mortality rates were lower for EVAR versus OAR [hazard ratio (HR) 0.74, 95% CI, 0.6-0.9], but not statistically different after 1 year (HR: 0.95, 95% CI, 0.8-1.2). This implies additional benefits to EVAR in the short term. Reintervention rates were higher after EVAR than OAR at 2 and 5 years (rate ratio: 1.79 95% CI, 1.2-2.7 and rate ratio:2.03 95% CI, 1.4-3.0), but not within the first year. Reintervention was associated with higher mortality risk for both OAR (HR: 1.66 95% CI, 1.1-2.5) and EVAR (HR: 2.14 95% CI, 1.6-2.9). Long-term mortality was similar between repair types (HR: 0.99, 95% CI, 0.8-1.2).

CONCLUSIONS

Within VQI/Medicare patients undergoing rAAA repair, the perioperative mortality rate favors EVAR but equalizes after 1 year. Reinterventions were more common after EVAR and were associated with higher mortality regardless of treatment.

Risk Prediction Models for Peri-Operative Mortality in Patients Undergoing Major Vascular Surgery with Particular Focus on Ruptured Abdominal Aortic Aneurysms: A Scoping Review

PURPOSE

The present scoping review aims to describe and analyze available clinical data on the most commonly reported risk prediction indices in vascular surgery for perioperative mortality, with a particular focus on ruptured abdominal aortic aneurysm (rAAA).

MATERIALS AND METHODS

A scoping review following the PRISMA Protocols Extension for Scoping Reviews was performed. Available full-text studies published in English in PubMed, Cochrane and EMBASE databases (last queried, 30 March 2023) were systematically reviewed and analyzed. The Population, Intervention, Comparison, Outcome (PICO) framework used to construct the search strings was the following: in patients with aortic pathologies, in particular rAAA (population), undergoing open or endovascular surgery (intervention), what different risk prediction models exist (comparison), and how well do they predict post-operative mortality (outcomes)?

RESULTS

The literature search and screening of all relevant abstracts revealed a total of 56 studies in the final qualitative synthesis. The main findings of the scoping review, grouped by the risk score that was investigated in the original studies, were synthetized without performing any formal meta-analysis. A total of nine risk scores for major vascular surgery or elective AAA, and 10 scores focusing on rAAA, were identified. Whilst there were several validation studies suggesting that most risk scores performed adequately in the setting of rAAA, none reached 100% accuracy. The Glasgow aneurysm score, ERAS and Vancouver score risk scores were more frequently included in validation studies and were more often used in secondary studies. Unfortunately, the published literature presents a heterogenicity of results in the validation studies comparing the different risk scores. To date, no risk score has been endorsed by any of the vascular surgery societies.

CONCLUSIONS

The use of risk scores in any complex surgery can have multiple advantages, especially when dealing with emergent cases, since they can inform perioperative decision making, patient and family discussions, and post hoc case-mix adjustments. Although a variety of different rAAA risk prediction tools have been published to date, none are superior to others based on this review. The heterogeneity of the variables used in the different scores impairs comparative analysis which represents a major limitation to understanding which risk score may be the "best" in contemporary practice. Future developments in artificial intelligence may further assist surgical decision making in predicting post-operative adverse events.

The Association Between Body Mass Index and Death Following Elective Endovascular and Open Repair of Abdominal Aortic Aneurysms in the Vascular Quality Initiative

OBJECTIVE

The effect of body mass index (BMI) on post-operative outcomes after abdominal aortic aneurysm (AAA) repair remains poorly defined. The association between BMI and death following elective endovascular aneurysm repair (EVAR) and open aneurysm repair (OAR) of AAA in a large national quality registry is investigated.

METHODS

All elective AAA repairs within the Society for Vascular Surgery Vascular Quality Initiative (VQI; 2010 to September 2021) were reviewed (EVAR, n = 53 426; OAR, n = 9 479). All analyses were conducted separately for EVAR and OAR patients. The primary end points were 30 day mortality and five year survival rates. Study cohorts were divided into World Health Organisation BMI categories (C1 < 18.5, C2 18.5 ≤ BMI < 25, C3 25 ≤ BMI < 30, C4, 30 ≤ BMI < 35, C5 35 ≤ BMI < 40, C6 ≥ 40). BMI was examined as both a categorical and continuous variable. Logistic and Cox proportional hazards regression were used for risk adjustment.

RESULTS

Among EVAR patients, BMI distribution was C1, 1 216 (2%); C2, 14 687 (28%); C3, 20 516 (38%); C4, 11 352 (21%); C5, 3 947 (7%); C6, 1 708 (3%). Class 1, 2, and 6 BMI patients experienced an increased 30 day mortality rate (C1 2.6%; C2 1.3%; C6 1.4% vs. C3 - 5 0.7%; p < .001) and C1 and C2 had correspondingly inferior long term survival (five years: C1 69 ± 3%; C2 79 ± 1% vs. C3 - 6 86 - 88 ± 2%; log rank p < .001). These survival disparities persisted after risk adjustment for multiple confounders. In the OAR cohort, BMI distribution was C1, 280 (3%); C2, 2 862 (30%); C3, 3 587 (38%); C4, 1 940 (21%); C5, 581 (6%); C6, 229 (2%). Crude 30 day mortality rates were increased for both the lowest and highest BMI patients (C1 12%, C6 7% vs. C2 - 5 3 - 4%; p < .001); these differences also persisted in long term survival (five years: C1 71 ± 6%, C6 82 ± 6% vs. C2 - 6 85 - 88 ± 3%; log rank p < .001). In risk adjusted analysis, both low and high BMI OAR patients had an increased 30 day and long term mortality rate.

CONCLUSION

Within the VQI, both the extreme low (< 18.5) and high (≥ 40) BMI groups experienced an increased 30 day mortality rate after both elective EVAR and OAR. By comparison, while the lowest BMI cohort was significantly associated with decreased long term survival after both procedures, the highest BMI group only experienced reduced long term survival after OAR. Based upon this large real world registry analysis of elective AAA repairs, differential metabolic signatures exist within extreme BMI categories, which may inform peri-operative risk stratification and clinical decision making.

Protein-lipid Association in Lizard Chemical Signals

Chemical communication in terrestrial vertebrates is often built on complex blends, where semiochemical and structural compounds may form an integrated functional unit. In lizards, many species have specialized epidermal glands whose secretions are waxy, homogeneous blends of lipids and proteins, both active in communication. The intimate co-occurrence of such compounds allows us to hypothesize that they should undergo a certain degree of covariation, considering both their semiochemical role and the support-to-lipid function hypothesized for the protein fraction. In order to assess the occurrence and level of protein-lipid covariation, we compared the composition and complexity of the two fractions in the femoral gland secretions of 36 lizard species, combining phylogenetically-informed analysis with tandem mass spectrometry. We found the composition and complexity of the two fractions to be strongly correlated. The composition of the protein fraction was mostly influenced by the relative proportion of cholestanol, provitamin D₃, stigmasterol, and tocopherol, while the complexity of the protein pattern increased with that of lipids. Additionally, two identified proteins (carbonic anhydrase and protein disulfide isomerase) increased their concentration as provitamin D₃ became more abundant. Although our approach does not allow us to decrypt the functional relations between the proteinaceous and lipid components, nor under the semiochemical or structural hypothesis, the finding that the proteins involved in this association were enzymes opens up to new perspectives about protein role: They may confer dynamic properties to the blend, making it able to compensate predictable variation of the environmental conditions. This may expand the view about proteins in the support-to-lipid hypothesis, from being a passive and inert component of the secretions to become an active and dynamic one, thus providing cues for future research.

A systematic review and meta-analysis of retrograde type A aortic dissection after thoracic endovascular aortic repair in patients with type B aortic dissection

BACKGROUND

Retrograde type A dissection (RTAD) is a devastating complication of thoracic endovascular repair (TEVAR) with low incidence but high mortality. The objective of this study is to report the incidence, mortality, potential risk factors, clinical manifestation and diagnostic modalities, and medical and surgical treatments.

METHODS

A systematic review and single-arm and two-arm meta-analyses evaluated all published reports of RTAD post-TEVAR through January 2021. All study types were included, except study protocols and animal studies, without time restrictions. Outcomes of interest were procedural data (implanted stent-grafts type, and proximal stent-graft oversizing), the incidence of RTAD, associated mortality rate, clinical manifestations, diagnostic workouts and therapeutic management.

RESULTS

RTAD occurred in 285 out of 10,600 patients: an estimated RTAD incidence of 2.3% (95% CI: 1.9-2.8); incidence of early RTAD was approximately 1.8 times higher than late. Wilcoxon signed-rank testing showed that the proportion of RTAD patients with acute type B aortic dissection (TBAD) was significantly higher than those with chronic TBAD (P = .008). Pooled meta-analysis showed that the incidence of RTAD with proximal bare stent TEVAR was 2.1-fold higher than with non-bare stents: risk ratio was 1.55 (95% CI: 0.87-2.75; P = .13). Single arm meta-analysis estimated a mortality rate of 42.2% (95% CI: 32.5-51.8), with an I2 heterogeneity of 70.11% (P < .001).

CONCLUSION

RTAD is rare after TEVAR but with high mortality, especially in the first month post-TEVAR with acute TBAD patients at greater risk as well as those treated with proximal bare stent endografts.

Scoping review of radiologic assessment and prognostic impact of skeletal muscle sarcopenia in patients undergoing endovascular repair for aortic disease

OBJECTIVE

The primary objectives of our scoping review were to evaluate the methods used by research groups to assess the incidence of sarcopenia in patients with aortic disease and the extent of the evidence base that links sarcopenia to the survival of patients undergoing elective endovascular aortic repair and to identify the recurring themes or gaps in the literature to guide future research.

METHODS

A scoping review in accordance with the PRISMA (preferred reporting items for systematic reviews and meta-analyses) protocols extension for scoping reviews was performed. The available studies included those fully reported in English (last query, April 30, 2022). The following PICO question was used to build the search equation: "in patients with aortic disease [population] undergoing endovascular repair [intervention], what was the prevalence and prognosis of radiologically defined sarcopenia [comparison] on the short- and long-term outcomes?"

RESULTS

A total of 31 studies were considered relevant, and 18 were included in the present scoping review. In brief, 12 studies had focused on standard endovascular aneurysm repair (EVAR), 2 on thoracic EVAR, and 4 on complex EVAR. All but two studies were retrospective in design, and only one study had included patients from a multicenter database. Sarcopenia had generally been defined using the computed tomography angiography (CTA) findings of the cross-sectional area of the psoas muscle at L3 or L4, sometimes with normalization against the height. Overall, despite the heterogeneity in the methods used for its definition, sarcopenia was highly prevalent (range, 12.5%-67.6%). The patients with sarcopenia had had higher rates of mortality (ratio ranged from 2.28 [95% confidence interval, 1.35-3.84] to 6.34 [95% confidence interval, 3.37-10.0]) and adverse events (41% vs 16%; P = .020).

CONCLUSIONS

Sarcopenia, as identified using computed tomography angiography-based measurements of the skeletal muscle mass, was prevalent among patients undergoing elective EVAR, thoracic EVAR, or complex EVAR. The presence of sarcopenia has been shown to have a negative prognostic impact, increasing the operative risk and has been linked to poorer long-term survival.

Use of linked registry claims data for long term surveillance of devices after endovascular abdominal aortic aneurysm repair: observational surveillance study

OBJECTIVE

To evaluate long term outcomes (reintervention and late rupture of abdominal aortic aneurysm) of aortic endografts in real world practice using linked registry claims data.

DESIGN

Observational surveillance study.

SETTING

282 centers in the Vascular Quality Initiative Registry linked to United States Medicare claims (2003-18).

PARTICIPANTS

20 489 patients treated with four device types used for endovascular abdominal aortic aneurysm repair (EVAR): 40.6% (n=8310) received the Excluder (Gore), 32.2% (n=6606) the Endurant (Medtronic), 16.0% (n=3281) the Zenith (Cook Medical), and 11.2% (n=2292) the AFX (Endologix). Given modifications to AFX in late 2014, patients who received the AFX device were categorized into two groups: the early AFX group (n=942) and late AFX group (n=1350) and compared with patients who received the other devices, using propensity matched Cox models.

MAIN OUTCOME MEASURES

Reintervention and rupture of abdominal aortic aneurysm post-EVAR; all patients (100%) had complete follow-up via the registry or claims based outcome assessment, or both.

RESULTS

Median age was 76 years (interquartile range (IQR) 70-82 years), 80.0% (16 386/20 489) of patients were men, and median follow-up was 2.3 years (IQR 0.9-4.1 years). Crude five year reintervention rates were significantly higher for patients who received the early AFX device compared with the other devices: 14.9% (95% confidence interval 13.7% to 16.2%) for Excluder, 19.5% (18.1% to 21.1%) for Endurant, 16.7% (15.0% to 18.6%) for Zenith, and early 27.0% (23.7% to 30.6%) for the early AFX. The risk of reintervention for patients who received the early AFX device was higher compared with the other devices in propensity matched Cox models (hazard ratio 1.61, 95% confidence interval 1.29 to 2.02) and analyses using a surgeon level instrumental variable of >33% AFX grafts used in their practice (1.75, 1.19 to 2.59). The linked registry claims surveillance data identified the increased risk of reintervention with the early AFX device as early as mid-2013, well before the first regulatory warnings were issued in the US in 2017.

CONCLUSIONS

The linked registry claims surveillance data identified a device specific risk in long term reintervention after EVAR of abdominal aortic aneurysm. Device manufacturers and regulators can leverage linked data sources to actively monitor long term outcomes in real world practice after cardiovascular interventions.

Factors Associated with Preference of Choice of Aortic Aneurysm Repair in the PReference for Open Versus Endovascular repair of AAA (PROVE-AAA) study

OBJECTIVE

Patients can choose between open repair and endovascular repair of abdominal aortic aneurysm (AAA). However, the factors associated with patient preference for one repair type over another are not well characterized. Here we assess the factors associated with preference of choice for open or endovascular AAA repair among veterans exposed to a decision aid to help with choosing surgical treatment.

METHODS

Across 12 VA hospitals, veterans received a decision aid covering domains including patient information sources and understanding preference. Veterans were then given a series of surveys at different timepoints examining their preferences for open versus endovascular AAA repair. Questions from the preference survey were used in analyses of patient preference. Results were analyzed using chi-squared tests. A logistic regression was performed to assess factors associated with preference for open repair or preference for endovascular repair.

RESULTS

A total of 126 veterans received a decision aid informing them of their treatment choices, after which 121 completed all preference survey questions; five veterans completed only part of the instruments. Overall, veterans who preferred open repair were typically younger (70 vs 73, p=0.02), with similar rates of common comorbidities (coronary disease 16% vs 28%, p=0.21), and similar aneurysms compared to those who preferred endovascular repair (6.0 cm versus 5.7 cm, p=0.50). Veterans in both preference categories (28% of veterans preferring EVAR, 48% of veterans preferring open repair) reported "taking their doctor's" advice as the "top-box" response for the single most important factor influencing their decision. When comparing the tradeoff between less invasive surgery and higher risk of long-term complications, more than half of veterans preferring EVAR reported invasiveness as more important compared with approximately one in ten of those preferring open repair (53% versus 12%, p<0.001). Shorter recovery was an important factor for the endovascular repair group (74%) and not important in the open repair group (76%), p=0.5). In multivariable analyses, valuing a short hospital stay (OR=12.4, 95% CI 1.13-135.7) and valuing a shorter recovery (OR15.72, 95% CI 1.03-240.2) were associated with greater odds of preference for endovascular repair, while finding these characteristics not important were associated with greater odds of preference for open repair.

CONCLUSIONS

When faced with the decision of open repair versus endovascular repair, veterans who valued a shorter hospital stay and a shorter recovery were more likely to prefer endovascular repair, while those more concerned about long-term complications preferred open repair. Veterans typically value the advice of their surgeon over their own beliefs and preference. These findings need to be considered by surgeons as they guide their patients to a shared decision.

Aortic Visceral Segment Instability is evident following Thoracic Endovascular Aortic Repair for Acute and Subacute Type B Aortic Dissection

BACKGROUND

Anatomic remodeling within the thoracic aorta following thoracic endovascular aortic repair (TEVAR) for type B aortic dissections (TBAD) has been well documented, but less is known about the response of the untreated visceral aorta. This study aims to investigate visceral aortic behavior following TEVAR for acute or subacute TBAD and identify associations with clinical outcomes.

METHODS

A multi-center retrospective review was performed of all imaging for all patients treated with TEVAR for acute (0-14 days) and subacute (14-90 days) non-traumatic TBAD between 2006-2020. Cohort was inclusive of uncomplicated, high-risk, and complicated (defined per SVS reporting guidelines) dissections. Centerline aortic measurements of the true and false lumen and total aortic diameter (TAD) were taken at standardized locations relative to aortic anatomy within each aortic zone (zones defined by SVS reporting guidelines). Diameter changes over time were evaluated using repeated measures mixed effects linear growth modeling. Visceral segment instability (VSI) was defined as any growth in TAD ≥ 5mm within aortic zones 5 through 9.

RESULTS

A total of 82 patients were identified. Median length of imaging follow-up was 2.1 years (IQR 3.9 years), with 15% of the cohort having follow-up longer than 5 years. VSI was present in 55% of the cohort, with an average maximal increase in TAD of 10.4±6.3 mm over a median follow-up of 2.1 years (IQR 3.9 years). Roughly a third of the cohort experienced rapid VSI (growth ≥5mm in first year), and 4.8% of the cohort developed a large para-visceral aneurysm aortic (TAD≥5cm) secondary to VSI. Linear growth modeling identified significant predictable growth in TAD across all visceral zones. Zones 7 had the highest rate of TAD dilation, with a fixed effect estimated rate of 1.3 mm per year (95%-CI 0.23-2.1, p=0.022). The preoperative factor most strongly associated with VSI was ≥6 cumulative number of zones dissected (OR 6.4, 95% OR 1.07-8.6, p=0.041). Odds for aortic reintervention were significantly increased in cases where VSI led to development of a para-visceral aortic aneurysm ≥5cm development (OR 3.7, 95%-CI 1.1-13, p=0.038).

CONCLUSION

VSI was identified in the majority of patients treated with TEVAR for management of acute and subacute TBAD. Preoperative anatomic features such as extent of dissection, rather than procedural details of graft coverage, may play a more significant role in VSI occurrence. Importantly, significant TAD growth occurred in all visceral segments. These results highlight the importance of lifelong surveillance following TEVAR, and identify a subset of patients that may be at increased risk for re-intervention.

Technical performance and reproducibility following rotational atherectomy of femoropopliteal artery occlusive lesions: analysis of the multicenter MORPHEAS Registry

BACKGROUND

The purpose of this study was to define patient and anatomical factors associated with technical results specific to rotational atherectomy. Controversy exists surrounding appropriate utilization of atherectomy to treat femoral-popliteal atherosclerosis. Importantly, the existence of different atherectomy devices and lack of technical reports highlighting variables that impact outcomes obscures the ability to assess perioperative performance.

METHODS

The nonindustry sponsored, Multicentric National Registry on the use of rotational atherectomy in femoral-popliteal occlusive atherosclerotic disease (MORPHEAS) database was queried. The MORPHEAS investigators included experienced providers at four centers who previously had not utilized rotational atherectomy. The primary endpoint was flow-limiting dissection and/or >50% recoil resulting in stent-placement while a secondary endpoint included peripheral thromboembolism incidence.

RESULTS

One hundred thirteen patients were enrolled. Only femoropopliteal occlusions were included in the analysis and anatomic distribution and calcification severity were depicted separately. The most common adjunctive therapy was drug-coated balloon angioplasty (84%; N.=96). Flow-limiting dissection was identified in 16% (N.=18) and thromboembolism occurred in 4% (N.=4). Diabetes increased risk of thromboembolism (P=0.03) while lesion length ≥8.0 cm (P=0.07) and SFA-popliteal adductor canal location (P=0.01) were associated with flow-limiting dissection. In multivariable analysis, SFA-popliteal adductor canal occlusion had a 4.7-fold risk of perioperative complications (OR=4.7, 95%CI: 1.1-21.0; P=0.04).

CONCLUSIONS

Rotational atherectomy was characterized by reproducible performance among four centers; however, diabetic patients, as well as those with long-segment, heavily calcified SFA-popliteal adductor canal occlusion present greatest risk of complications.

Short-Term Concerns Primarily Determine Patient Preference for Abdominal Aortic Aneurysm Repair

INTRODUCTION

Abdominal aortic aneurysm (AAA) repair may be performed through open or endovascular approaches, but the factors influencing a patient's repair-type preference are not well characterized. Here we performed a qualitative analysis to better understand factors influencing patient preference within the Preference for Open Versus Endovascular Repair of AAA Trial.

METHODS

Open-ended responses regarding primary (n = 21) and secondary (n = 47) factors influencing patient preference underwent qualitative analysis using the constant comparative method with iterative reviews. Codes were used to generate themes and themes grouped into categories, with each step conducted via consensus agreement between three researchers. Relative prevalence of themes were compared to ascertain trends in patient preference.

RESULTS

Patient responses regarding both primary and secondary factors fell into four categories: Short-term concerns, long-term concerns, advice & experience, and other. Patients most frequently described short-term concerns (23) as their primary influence, with themes including post-op complications, hospitalization & recovery, and intraoperative concerns. Long-term concerns were more prevalent (20) as secondary factors, which included themes such as survival, and chronic management. The average age of patients voicing only long-term concerns as a primary factor was 11 years younger than those listing only short-term concerns.

CONCLUSION

Short-term concerns relating to the procedure and recovery are more often the primary factor influencing patient preference, while long term concerns play a more secondary role. Long-term concerns are more often a primary factor in younger patients. Vascular surgeons should consider this information in shared decision making to reach an optimal outcome.

Carotid Stent Explant Indications and Outcomes

BACKGROUND

Carotid artery stenting is an alternative to carotid endarterectomy, especially in patients deemed to have significant anatomic or medical risk for the latter. There is scant literature, however, on indications for and outcomes of carotid stent (CAS) explant. We sought to determine indications and outcomes of CAS explant at our institution.

METHODS

We queried a prospectively maintained institutional vascular surgery database as well as hospital records to identify patients undergoing carotid stent explant from 2010-2020. Ten patients were identified. Their charts were reviewed to obtain demographic, comorbidity, procedural, and outcomes data. Data of particular interest were preoperative atherosclerotic factors, indications for CAS explant, carotid repair strategy, and 30-day post-procedural complications. Data were analyzed for ranges and means.

RESULTS

Ten patients were identified. Comorbidity was common: all patients had at least 1 atherosclerotic risk factor, with hypertension and hypercholesterolemia being the most common. Seven (70.0%) patients had recurrent stenosis as the indication for explant. Seven (70.0%) presented symptomatically. Five (50.0%) cases of restenosis had been refractory to angioplasty. There were 3 (30.0%) instances of CAS explant due to infection. Only 1 (12.5%) index CAS was performed at our institution. There was a mean hospital length of stay of 4.5 days. One patient had vocal cord paralysis requiring no intervention. There was no (0%) 30-day mortality, stroke, or postoperative wound infections.

CONCLUSIONS

Our series had 0% 30-day mortality, stroke, and postoperative wound infection suggesting that CAS explant may be performed safely. Our series is small but represents the largest single institution series to date. This procedure may become increasingly common in the coming years with the more frequent use of CAS; additional data is needed to rigorously understand outcomes.

Systematic review with pooled data analysis reveals the need for a standardized reporting protocol including the visceral vessels during fenestrated endovascular aortic repair (FEVAR)

OBJECTIVES

To collect and analyse the available evidence in the outcomes of patients treated with fenestrated endovascular aortic repair (f-EVAR) technique focusing specifically on visceral vessel outcomes.

METHODS

The current meta-analysis was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. All the studies reporting the f-EVAR technique for the management of degenerative pararenal and/or type IV thoracoabdominal aortic aneurysms (TAAA) were considered eligible for inclusion in the study. The main study outcomes (technical success, type I endoleaks, fracture or occlusion of the bridging stents, overall aneurysm-related mortality, and the reintervention rate) were subsequently expressed as proportions and 95% confidence intervals.

RESULTS

Fourteen studies with a total of 1804 patients were included in a pooled analysis. The technical success of the procedure was 95.97% (95%CI = 92.35-98.60). Intraoperatively, the pooled proportion of reported type I endoleak was 7.6% (95%CI = 2.52-14.60) while during a median follow-up of 41 months (range 11-96) follow-up period the pooled rate of fracture and occlusion of the bridging stents was 2.79% (95%CI = 0.00-8.52) and 4.46% (95%CI = 1.93-7.77), respectively. The overall aneurysm-related mortality was detected to be 0.63% (95%CI = 0.04-1.63), and the pooled estimate for re-intervention rate was 15.69%.

CONCLUSIONS

Fenestrated endovascular repair for p-AAA is an effective and safe treatment. Target vessel complications and endoleaks remain the two most important concerns for fenestrated endovascular procedures, contributing to most of the secondary interventions. The lack of computed tomography angiography follow-up evaluation does not allow us to draw robust conclusions about the complication rates for the superior mesenteric artery during f-EVAR. Due to the potential implications of SMA complications on aneurysm-related mortality, standardized reporting of short- and long-term target visceral vessel outcomes is required.

Impact of aortic stent-graft oversizing on outcomes of the chimney endovascular technique based on a new analysis of the PERICLES Registry

OBJECTIVE

Chimney endovascular aortic aneurysm repair is gaining ever greater acceptance. However, persistent gutters leading to type IA endoleaks represent an unsolved issue. The aim of the current study was to analyze the impact of abdominal endograft oversizing to the occurrence of this phenomenon.

METHODS

The PERformance of the snorkel/chImney endovascular teChnique in the treatment of compLex aortic PathologiesES registry includes the largest experience with chimney endovascular aortic aneurysm repair from 13 vascular centers in Europe and the U.S. Prospectively collected data from centers with standard use of the Endurant stent-graft and balloon-expandable covered stents as chimney grafts only were included in the present analysis. The parameter which varied was the degree of oversizing of the aortic stent-graft classifying the cohort in two groups, group A (20% and less oversizing) and group B (>20% of oversizing). The primary endpoint was the incidence of persistent type IA endoleak needed reintervention. Secondary endpoints were all-cause mortality and freedom from reintervention.

RESULTS

Group A included 21 patients while group B 144. The mean preoperative pathology's neck length and diameter was 5.8 mm (±4.4) versus 4.9 mm (±3.8) and 27.6 mm (±4.7) versus 24.9 mm (±3.7) for group A and group B, respectively. The mean length of the new sealing zone after chimney graft placement was similar for both groups (group A versus group B; 17.9 mm versus 18.3 mm, respectively, P = .21). The percentage of oversizing of the aortic stent-graft ranged between 13.8 and 20% versus 22.2 and 30%, for group A and group B, respectively. Patients of group A had more type 1A endoleaks, (14.3%) versus patients of group B (2.1%) based on the first follow-up imaging, P = .02. The incidence of persistent type IA endoleaks needing a reintervention was 14.3 and 1.4% for the group A and group B, respectively, P = .01. The mean volume of contrast medium used was greater in group A versus group B with 239 ml versus150 ml, P = .05. Additionally, 14.3% of patients of group A experienced acute renal failure compared to those in group B which was 1.0%, P = .01.

CONCLUSIONS

Oversizing of ideally 30% of the Endurant stent-graft is associated with significant lower incidence of type IA endoleaks requiring reintervention for patients treated by chimney endovascular aortic aneurysm repair.

Gender-related outcomes of chimney EVAR within the PERICLES registry

Objective

Gender-related differences in outcomes in complex endovascular aortic repair have not been profoundly investigated. Use of low profile abdominal devices as in chimney endovascular repair may be beneficial for female patients with pararenal pathologies. With the chimney technique, there is no need for large introduction sheaths. This could be an advantage in case of smaller in diameter iliac access especially in combination with stenosis or elongation. Aim of the present study was to compare the perioperative and mid-term outcomes between males and females patients treated with the chimney/snorkel technique for pararenal aortic pathologies.

Methods

The PERICLES registry collected the world wide experience with the chimney technique. According to the gender, patients were classified in two cohorts. Primary endpoints were freedom from occlusion of the chimney grafts and reintervention. Secondary endpoints included access site complications and need for surgical or interventional revision, Endoleak Type I rate, 30-day overall complications and mortality. Univariate comparison P-values were generated using either the likelihood ratio χ2 test, the Fisher exact test, the Wilcoxon rank sum test, or the log rank test. Kaplan–Meier curves estimated the outcomes in the long run.

Results

A total of 412 patients underwent Ch-EVAR, 71 (17%) females and 341 (83%) males with a mean age for both groups being 74 years were included in the present study. After 36 months of mean follow-up, no statistically significant difference was observed between the two cohorts regarding re-interventions ( P= .44). Freedom from occlusion rates at 36 months did not differed between the two groups (females 84% vs. 80% for males ( P= .033). For patients receiving more than one chimney stent, the odds of having a complication did not differ between males and females (M:F OR = 2.0, 95% CI: 0.6–6.4, P = 0.228); 30-day mortality was 0% in the female group, instead five male patients died within one month. ( P = 0.59). The incidence of acute renal failure was low in both groups without statistical difference: 2 (3.1%) vs. 13 (4.6%) 58 ( P = 1.00). Neither patient received an endoconduit to insert the abdominal device.

Conclusions

No statistically significant difference regarding the freedom from reintervention and chimney graft patency was observed between the two genders. The results highlight the beneficial use of the chimney technique in female patients who can have potentially higher risk of access complications.

Epidemiology, outcomes, and management of acute kidney injury in the vascular surgery patient

OBJECTIVE

Conventional clinical wisdom has often been nihilistic regarding the prevention and management of acute kidney injury (AKI), despite its being a frequent and morbid complication associated with both increased mortality and cost. Recent developments have shown that AKI is not inevitable and that changes in management of patients can reduce both the incidence and morbidity of perioperative AKI. The purpose of this narrative review was to review the epidemiology and outcomes of AKI in patients undergoing vascular surgery using current consensus definitions, to discuss some of the novel emerging risk stratification and prevention techniques relevant to the vascular surgery patient, and to describe a standardized perioperative pathway for the prevention of AKI after vascular surgery.

METHODS

We performed a critical review of the literature on AKI in the vascular surgery patient using the PubMed and MEDLINE databases and Google Scholar through September 2017 using web-based search engines. We also searched the guidelines and publications available online from the organizations Kidney Disease: Improving Global Outcomes and the Acute Dialysis Quality Initiative. The search terms used included acute kidney injury, AKI, epidemiology, outcomes, prevention, therapy, and treatment.

RESULTS

The reported epidemiology and outcomes associated with AKI have been evolving since the publication of consensus criteria that allow accurate identification of mild and moderate AKI. The incidence of AKI after major vascular surgery using current criteria is as high as 49%, although there are significant differences, depending on the type of procedure performed. Many tools have become available to assess and to stratify the risk for AKI and to use that information to prevent AKI in the surgical patient. We describe a standardized clinical assessment and management pathway for vascular surgery patients, incorporating current risk assessment and preventive strategies to prevent AKI and to decrease its complications. Patients without any risk factors can be managed in a perioperative fast-track pathway. Those patients with positive risk factors are tested for kidney stress using the urinary biomarker TIMP-2•IGFBP7, and care is then stratified according to the result. Management follows current Kidney Disease: Improving Global Outcomes guidelines.

CONCLUSIONS

AKI is a common postoperative complication among vascular surgery patients and has a significant impact on morbidity, mortality, and cost. Preoperative risk assessment and optimal perioperative management guided by that risk assessment can minimize the consequences associated with postoperative AKI. Adherence to a standardized perioperative pathway designed to reduce risk of AKI after major vascular surgery offers a promising clinical approach to mitigate the incidence and severity of this challenging clinical problem.

Collected Transatlantic Experience From the PERICLES Registry: Use of Chimney Grafts to Treat Post-EVAR Type Ia Endoleaks Shows Good Midterm Results

Purpose: The aim of this retrospective analysis was to evaluate the performance of the chimney (ch) technique in the treatment of type Ia endoleaks after standard endovascular aneurysm repair (EVAR). Methods: Between January 2008 and December 2014, 517 chEVAR procedures were performed in 13 US and European vascular centers (PERICLES registry). Thirty-nine patients (mean age 76.9±7.1 years; 33 men) were treated for persistent type Ia endoleak and had computed tomography angiography or magnetic resonance angiography follow-up at >1 month. Endurant abdominal stent-grafts were used in the 20 cases. Single chimney graft placement was performed in 18 (46%) patients and multiple in 21 (54%). Overall, 70 visceral vessels were targeted for revascularization. Results: Technical success was achieved in 35 (89.7%) cases; 3 persistent type Ia endoleaks and 1 chimney graft occlusion were detected within the first 30 days. Thirty-day mortality was 2.6%. Two other deaths (not aneurysm related) occurred during a mean follow-up of 21.9 months (0.23–71.3). Primary patency of the chimney grafts was 94.3% at 36 months. In a subgroup analysis comparing Endurant to other stent-grafts, no significant differences were observed regarding persistent endoleak [1/20 (5%) vs 2/19 (11%), p=0.6] or reintervention [1/20 (5%) vs 0/19 (0%)]. Conclusion: The present series demonstrates that chEVAR in the treatment of post-EVAR type Ia endoleaks has satisfactory results independent of the abdominal and chimney graft combinations. Midterm results show that chEVAR is an effective method for treating type Ia endoleaks.

Cardiovascular-Specific Mortality and Kidney Disease in Patients Undergoing Vascular Surgery

IMPORTANCE

Acute kidney injury (AKI) affects as many as 40% of patients undergoing surgery and is associated with increased all-cause mortality. Chronic kidney disease (CKD) is a well-known risk factor for cardiovascular mortality.

OBJECTIVE

To determine the association between kidney disease and long-term cardiovascular-specific mortality after vascular surgery.

DESIGN, SETTING, AND PARTICIPANTS

A single-center cohort of 3646 patients underwent inpatient vascular surgery from January 1, 2000, to November 30, 2010, at a tertiary care teaching hospital. To determine cause-specific mortality for patients undergoing vascular surgery, a proportional subdistribution hazards regression analysis was used to model long-term cardiovascular-specific mortality while treating any other cause of death as a competing risk. Kidney disease constituted the main covariate after adjusting for baseline patient characteristics, surgery type, and admission hemoglobin level. Final follow-up was completed July 2014 to assess survival through January 31, 2014, and data were analyzed from June 1, 2014, to September 7, 2015.

MAIN OUTCOMES AND MEASURES

Perioperative AKI, presence of CKD, and overall and cause-specific mortality.

RESULTS

Among the 3646 patients undergoing vascular surgery, perioperative AKI occurred in 1801 (49.4%) and CKD was present in 496 (13.6%). The top 2 causes among the 1577 deaths in our cohort were cardiovascular disease (845 of 1577 [53.6%]) and cancer (173 of 1577 [11.0%]). Adjusted cardiovascular mortality estimates at 10 years were 17%, 31%, 30%, and 41%, respectively, for patients with no kidney disease, AKI without CKD, CKD without AKI, and AKI with CKD. Adjusted hazard ratios (95% CIs) for cardiovascular mortality were significantly elevated among patients with AKI without CKD (2.07 [1.74-2.45]), CKD without AKI (2.01 [1.46-2.78]), and AKI with CKD (2.99 [2.37-3.78]) and were higher than those for other risk factors, including increasing age (1.03 per 1-year increase; 1.02-1.04), emergent surgery (1.47; 1.27-1.71), and admission hemoglobin levels lower than 10 g/dL (1.39; 1.14-1.69) compared with a hemoglobin level of 12 g/dL or higher.

CONCLUSIONS AND RELEVANCE

Perioperative AKI is common in patients undergoing vascular surgery and is associated with a high risk for cardiovascular-specific mortality comparable to that seen with CKD. These findings reinforce the importance of preoperative and postoperative risk stratification for kidney disease and the implementation of strategies now available to help prevent perioperative AKI.

Variation in hospital costs and reimbursement for endovascular aneurysm repair: A Vascular Quality Initiative pilot project

OBJECTIVE

Comparing costs between centers is difficult because of the heterogeneity of vascular procedures contained in broad diagnosis-related group (DRG) billing categories. The purpose of this pilot project was to develop a mechanism to merge Vascular Quality Initiative (VQI) clinical data with hospital billing data to allow more accurate cost and reimbursement comparison for endovascular aneurysm repair (EVAR) procedures across centers.

METHODS

Eighteen VQI centers volunteered to submit UB04 billing data for 782 primary, elective infrarenal EVAR procedures performed by 108 surgeons in 2014. Procedures were categorized as standard or complex (with femoral-femoral bypass or additional arterial treatment) and without or with complications (arterial injury or embolectomy; bowel or leg ischemia; wound infection; reoperation; or cardiac, pulmonary, or renal complications), yielding four clinical groups for comparison. MedAssets, Inc, using cost to charge ratios, calculated total hospital costs and cost categories. Cost variation analyzed across centers was compared with DRG 237 (with major complication or comorbidity) and 238 (without major complication or comorbidity) coding. A multivariable model to predict DRG 237 coding was developed using VQI clinical data.

RESULTS

Of the 782 EVAR procedures, 56% were standard and 15% had complications, with wide variation between centers. Mean total costs ranged from $31,100 for standard EVAR without complications to $47,400 for complex EVAR with complications and varied twofold to threefold among centers. Implant costs for standard EVAR without complications varied from $8100 to $28,200 across centers. Average Medicare reimbursement was less than total cost except for standard EVAR without complications. Only 9% of all procedures with complications in the VQI were reported in the higher reimbursed DRG 237 category (center range, 0%-21%). There was significant variation in hospitals' coding of DRG 237 compared with their expected rates. VQI clinical data accurately predict current DRG coding (C statistic, 0.87).

CONCLUSIONS

VQI data allow a more precise EVAR cost comparison by identifying comparable clinical groups compared with DRG-based calculations. Total costs exceeded Medicare reimbursement, especially for patients with complications, although this varied by center. Implant costs also varied more than expected between centers for comparable cases. Incorporation of VQI data elements documenting EVAR case complexity into billing data may allow centers to better align respective DRG reimbursement to total costs.

Variations in Abdominal Aortic Aneurysm Care: A Report From the International Consortium of Vascular Registries

BACKGROUND

This project by the ICVR (International Consortium of Vascular Registries), a collaboration of 11 vascular surgical quality registries, was designed to evaluate international variation in the contemporary management of abdominal aortic aneurysm (AAA) with relation to recommended treatment guidelines from the Society for Vascular Surgery and the European Society for Vascular Surgery.

METHODS

Registry data for open and endovascular AAA repair (EVAR) during 2010 to 2013 were collected from 11 countries. Variations in patient selection and treatment were compared across countries and across centers within countries.

RESULTS

Among 51 153 patients, 86% were treated for intact AAA (iAAA) and 14% for ruptured AAA. Women constituted 18% of the entire cohort (range, 12% in Switzerland-21% in the United States; P<0.01). Intact AAAs were repaired at diameters smaller than recommended by guidelines in 31% of men (<5.5 cm; range, 6% in Iceland-41% in Germany; P<0.01) and 12% of women with iAAA (<5 cm; range, 0% in Iceland-16% in the United States; P<0.01). Overall, use of EVAR for iAAA varied from 28% in Hungary to 79% in the United States (P<0.01) and for ruptured AAA from 5% in Denmark to 52% in the United States (P<0.01). In addition to the between-country variations, significant variations were present between centers in each country in terms of EVAR use and rate of small AAA repair. Countries that more frequently treated small AAAs tended to use EVAR more frequently (trend: correlation coefficient, 0.51; P=0.14). Octogenarians made up 23% of all patients, ranging from 12% in Hungary to 29% in Australia (P<0.01). In countries with a fee-for-service reimbursement system (Australia, Germany, Switzerland, and the United States), the proportions of small AAA (33%) and octogenarians undergoing iAAA repair (25%) were higher compared with countries with a population-based reimbursement model (small AAA repair, 16%; octogenarians, 18%; P<0.01). In general, center-level variation within countries in the management of AAA was as important as variation between countries.

CONCLUSIONS

Despite homogeneous guidelines from professional societies, significant variation exists in the management of AAA, most notably for iAAA diameter at repair, use of EVAR, and the treatment of elderly patients. ICVR provides an opportunity to study treatment variation across countries and to encourage optimal practice by sharing these results.