Differences in patient selection and outcomes based on abdominal aortic aneurysm diameter thresholds in the Vascular Quality Initiative

The association of ruptured abdominal aortic aneurysm diameter with mortality in the International Consortium of Vascular Registries

BACKGROUND

The mortality after ruptured abdominal aortic aneurysm (rAAA) repair is high, despite improvements in perioperative care, centralization of emergency vascular surgical services, and the introduction of endovascular aneurysm repair (EVAR). The diameter of intact AAA has been shown to be a predictor of short- and long-term survival. The aim of this study was to analyze the impact of AAA diameter on mortality for rAAA repair using contemporary data collected from the International Consortium of Vascular Registries and compare outcomes by sex and the type of repair patients received.

METHODS

Prospective registry data on repair of rAAA from seven countries were collected from 2010 to 2016. The primary outcome was perioperative mortality after EVAR and open surgical repair (OSR). Data were stratified by type of repair and sex. Logistic regression models were used to estimate odds ratio (OR) for the association between AAA diameter and perioperative mortality and the association between type of repair and mortality. Multivariable logistic regression models were used to adjust for differences in patient characteristics.

RESULTS

The study population consisted of 6428 patients with a mean age ranging from 70.2 to 75.4 years; the mean AAA diameter was 7.7 ± 1.8 cm. Females had a significantly smaller AAA diameter at presentation compared with males (6.9 ± 1.6 cm vs 7.9 ± 1.8 cm; P < .001). who underwent OSR had larger AAA diameters compared with those who underwent EVAR (P < .001). Females who underwent repair were significantly older (P < .001). Males were more likely to have cardiac disease, diabetes mellitus, and renal impairment. Overall, AAA diameter was a predictor of mortality in univariate and multivariate analysis. When analyzing EVAR and OSR separately, the impact of AAA diameter per cm increase on mortality was apparent in both males and females undergoing EVAR, but not OSR (EVAR: male OR, 1.09 [95% confidence interval, 1.03-1.16] and EVAR: female OR, 1.17 [95% confidence interval, 1.02-1.35]). The early mortality rate for males and females who underwent EVAR was 18.9% and 25.9% (P < .001), respectively. The corresponding mortality for males and females who underwent OSR was 30.2% and 38.6% (P < .001), respectively.

CONCLUSIONS

In these real-world international data, there is a significant association between rAAA diameters and early mortality in males and females. This association was more evident in patients undergoing EVAR, but not shown in OSR. Despite improvements in overall AAA repair outcomes, the risk of mortality after rAAA repair is consistently higher for females.

Association of women-specific size threshold and mortality in elective abdominal aortic aneurysm repair

BACKGROUND

It is unclear whether women derive mortality benefit from early repair of abdominal aortic aneurysms (AAA). The aim of this study was to compare short- and mid-term mortality for women treated at small versus large diameters.

METHOD

Women receiving elective repair of AAA at small (49-54 mm) and large (≥55 mm) diameters from 2008 to 2022 were extracted from the Swedish National Registry for Vascular Surgery (n = 1642 women). The effect of diameter on 90-day, 1- and 3-year mortality was studied in logistic regression and propensity score models. Age, co-morbidities, smoking and repair modality were considered as confounders. Men (n = 9047) were analysed in parallel.

RESULTS

Some 1642 women were analysed, of whom 34% underwent repair at small diameters (versus 52% of men). Women with small (versus large) AAAs were younger (73 versus 75 years, P < 0.001), and 63% of women in both size groups had endovascular repairs (P = 0.120). Mortality was 3.5% (90 days), 7.1% (1 year) and 15.8% (3 years), with no differences between the size strata. There was no consistent association between AAA size and mortality in multivariable models. Sex differences in mortality were almost entirely due to mortality in younger-than-average women versus men (3-year mortality: small AAAs 11.1% versus 7.3%, P < 0.030, or large 14.4% versus 10.7%, P < 0.038).

CONCLUSION

Mortality in women is high and unaffected by AAA size at repair. The optimal threshold for women remains undefined. The higher rupture risk in women should not automatically translate into a lower, women-specific threshold.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Thoracoabdominal aortic aneurysm life-altering events following endovascular aortic repair in the Vascular Quality Initiative

OBJECTIVE

Endovascular aortic aneurysm repair has lower rates of postoperative mortality and morbidity when compared with open repair. However, endovascular repair still carries the risk of postoperative dialysis, paralysis, and stroke. This study examined the rates of postoperative mortality and morbidity stratified by type of endovascular aortic aneurysm repair.

METHODS

All patients who underwent endovascular aortic aneurysm repair in the Vascular Quality Initiative registry from January 2011 - May 2022 were identified. Patients were stratified by repair type: infrarenal endovascular aortic repair (EVAR), complex EVAR, thoracic endovascular aortic repair (TEVAR), extent I-III thoracoabdominal aortic aneurysm (TAAA) repair, or aortic arch repair. The primary outcome was postoperative thoracoabdominal aortic aneurysm life-altering events (TALE) across the different treatment groups. TALE was defined as a composite outcome of postoperative mortality, dialysis, paralysis, and/or stroke. Mixed effect logistic regression modeling was used to identify procedural and anatomic factors that were independently associated with TALE.

RESULTS

A total of 52,592 EVARs, 3,768 complex EVARs, 3,899 TEVARs, 1,139 extent I-III TAAA repairs, and 479 arch repairs were identified. TALE was observed in 1.2% of EVARs, 4.8% of complex EVARs, 6.0% of TEVARs, 10% of extent I-III TAAA repairs, and 14% of arch repairs. More proximal landing zone was associated with higher odds of TALE after complex EVAR (OR 1.9 [1.2-3.1]; p=.008), TEVAR (OR 2.2 [1.4-3.5]; p=.001), and extent I-III TAAA repair (OR 2.7 [1.5-4.9]; p=.001). Aortic diameter >65mm was associated with higher odds of TALE after infrarenal EVAR (OR 1.8 [1.4-2.3]; p<.001), complex EVAR (OR 1.6 [1.1-2.3]; p=.010), TEVAR (OR 2.7 [2.0-3.8]; p<.001), and arch repair (OR 2.4; [1.3-4.4]; p=.007). The use of parallel grafting technique (chimney/snorkel/periscope) during extent I-III TAAA repair was also associated with higher odds of TALE (OR 1.8 [1.1-3.2]; p=.032). Preoperative chronic kidney disease was also associated with higher odd of TALE after infrarenal EVAR (OR 4.3 [3.0-5.7]; p<.001), complex EVAR (OR 5.2 [3.3-8.2]; p<.001), TEVAR (OR 4.5 [2.8-7.1]; p<.001), and extent I-III TAAA repair (OR 3.2 [1.6-6.7]; p=.001).

CONCLUSION

While TALE was originally described for thoracoabdominal aortic aneurysm repairs, TALE may occur after complex EVAR, TEVAR, and arch repairs as well. Therefore, TALE and its component parts should be used to evaluate the efficacy of all aortic repairs and for preoperative counseling. Additionally, surgeons should be aware of anatomic and procedural characteristics that are associated with higher odds of TALE. The anticipated need for such interventions during aortic repair should be factored into preoperative risk assessment of patients.

Limb graft occlusion after endovascular aneurysm repair with the Cook Zenith Alpha abdominal graft

OBJECTIVE

Prior reports of the low profile Zenith Alpha abdominal graft (Cook Medical Inc, Bloomington, IN) have shown impaired limb graft patency to be the primary causes of reintervention. Special notices from the manufacturer have indicated certain instructions for use (IFU) violations as the main reasons for these complications. In the present study, we assessed the incidence of limb graft occlusion (LGO) and analyzed the effects of the detailed anatomic risk factors for LGO highlighted in the IFU and previously reported studies.

METHODS

A retrospective study was performed of 241 patients treated with the low profile Zenith Alpha at a single institution from October 1, 2015 to September 30, 2018. All computed tomography angiograms were analyzed using three-dimensional software. Data were extracted from the electronic medical records until the end of the study period (December 31, 2020). The cumulative incidence of LGO and LGO-related reinterventions were assessed. A regression analysis was performed to evaluate the possible risk factors associated with the development of LGO at specified time points. These included aortic and iliac diameters, graft component oversizing, iliac tortuosity and calcification, overlap of graft components, proximal alignment of ipsilateral and contralateral legs, and sealing zone in the external iliac artery. Reader agreement of iliac calcification and tortuosity was assessed in patients with LGO.

RESULTS

A total of 33 limbs (7%) in 27 patients (11%) had become occluded. The cumulative incidence of LGO was 7% (95% confidence interval [CI], 5%-9%) per limb up to 3 years postoperatively. The previously described risk factors for LGO were studied using regression analysis; however, no positive association with LGO was identified. Heavily calcified common iliac arteries (CIAs) and external iliac arteries were protective against LGO compared with noncalcified vessels up to 3 years postoperatively (decreased risk, 17% [95% CI, -27% to -7%]; P = .001; and 15% [95% CI, -26 to -5]; P = .005, respectively). The reader agreement of iliac calcification and tortuosity showed substantial agreement (CIA intrareader kappa = 0.75; CIA interreader kappa = 0.62) and almost perfect agreement (intrareader kappa = 0.85; interreader kappa = 0.84), respectively.

CONCLUSIONS

The cumulative incidence of LGO after endovascular aneurysm repair with the Zenith Alpha graft was 7% per limb up to 3 years postoperatively. None of the analyzed risk factors suggested by the IFUs or current literature were positively associated with LGO.

Excess Mortality for Abdominal Aortic Aneurysms and the Potential of Strict Implementation of Cardiovascular Risk Management: A Multifaceted Study Integrating Meta-Analysis, National Registry, and PHAST and TEDY Trial Data

OBJECTIVE

Previous studies imply a profound residual mortality risk following successful abdominal aorta aneurysm (AAA) repair. This excess mortality is generally attributed to increased cardiovascular risk. The aim of this study was (1) to quantify the excess residual mortality for patients with AAA, (2) to evaluate the cross sectional level of cardiovascular risk management, and (3) to estimate the potential of optimised cardiovascular risk management to reduce the excess mortality in these patients.

METHODS

Excess mortality was estimated through a systematic review and meta-analysis, and through data from the Swedish National Health Registry. Cardiovascular risk profiles were individually assessed during eligibility screening of patients with AAA for two multicentre pharmaceutical AAA stabilisation trials. The potential of full implementation of cardiovascular risk management was estimated through the validated Second Manifestations of ARTerial disease (SMART) risk scores algorithm.

RESULTS

The meta-analysis showed a similarly impaired survival for patients who received early repair (small AAA) or regular repair (≥ 55 mm), and a further impaired survival for patients under surveillance for a small AAA. Excess mortality was further quantified using Swedish population data. The data revealed a more than quadrupled and doubled five year mortality rate for women and men who had their AAA repaired, respectively. Evaluation of the level of risk management of 358 patients under surveillance in 16 Dutch hospitals showed that the majority of patients with AAA did not meet therapeutic targets set for risk management in high risk populations, and indicated a more pronounced prevention gap in women. Application of the SMART risk score algorithm predicted that optimal implementation of risk management guidelines would reduce the 10 year risk of major adverse cardiovascular events from 43% to 14%.

CONCLUSION

Independent of the rupture risk, AAA is associated with a worryingly compromised life expectancy with a particularly poor prognosis for women. Optimal implementation of cardiovascular risk prevention guidelines is predicted to profoundly reduce cardiovascular risk.

Sex difference in early mortality after abdominal aortic aneurysm repair

OBJECTIVE

Although female patients have a lower prevalence of abdominal aortic aneurysm (AAA), they seem to have a worse treatment outcome compared with male patients. Both maximum aneurysm diameter and aortic size index (ASI) are important indicators of the risk of AAA rupture, among which ASI has been shown capable of equalizing sex-related anatomical differences. Our study aimed to investigate whether sex is an independent risk factor for early postoperative mortality and how the diameter or ASI affects the association between sex and mortality.

METHODS

We performed a retrospective analysis of patients who enrolled in the AAA registry of the German Society of Vascular Surgery from 2013 to 2019. The patients were treated by either open surgical repair (OSR) or endovascular aneurysm repair (EVAR). The association between sex and 30-day mortality was investigated using logistic regression analysis. The interaction and mediating effects of maximum aneurysm diameter and ASI were investigated to verify their roles in the effect of sex on mortality. The relationships between the diameter (or ASI) and the risk of 30-day mortality in different sexes were demonstrated by the restricted cubic spline.

RESULTS

Overall, 23,275 cases were included in our analysis, with 20,130 male (86.5%) and 3139 female (13.5%) patients. Female patients had a smaller maximum aneurysm diameter (OSR, 55.23 ± 10.29 mm vs 58.05 ± 11.28 mm [P < .001]; EVAR, 54.06 ± 9.08 mm vs 56.11 ± 9.38 mm [P < .001]), but a higher ASI (OSR, 3.16 ± 0.71 vs 2.92 ± 0.69 [P < .001]; EVAR, 3.05 ± 0.66 vs 2.80 ± 0.59 [P < .001]) compared with male patients. The 30-day mortality rate was higher for female patients in both OSR (6.6% vs 4.2%; P = .002) and EVAR groups (1.8% vs 0.8%; P < .001). Logistic regression confirmed a significantly higher risk of 30-day mortality for female patients compared with male patients (odds ratio, 1.55; 95% confidence interval, 1.21-1.99; P = .001). No interaction was found between sex and diameter or ASI, but there were mediating effects for diameter and ASI in the effect of sex on 30-day mortality. For female patients, the risk of 30-day mortality linearly increased with the increase of diameter (P_Nonlinear = .089) or ASI (P_Nonlinear = .888), whereas the risk for male patients was U-shaped (for diameter, P_Nonlinear < .001; for ASI, P_Nonlinear = .020).

CONCLUSIONS

Sex is an independent risk factor for 30-day mortality after AAA repair. Both diameter and ASI are mediating factors for the effect of sex on 30-day mortality. The relationship between diameter or ASI and the risk of 30-day mortality is different for male and female patients.

Characterizing the frequency and indications for repair of abdominal aortic aneurysms with diameters smaller than recommended by societal guidelines

OBJECTIVE

While the Society for Vascular Surgery recommends repair of abdominal aortic aneurysms (AAA) at ≥5.5 cm in men and ≥5.0 cm in women, AAA repair below these thresholds has been well documented. There are clear indications for repair other than these strict size criteria, but the expected proportion of such repairs in one's practice has not been studied. We sought to characterize the indications for repairs of aneurysms below diameter recommendations at a single academic center. Using the assumption that this real-world experience would approximate that of other practices, we then used national data to extrapolate these findings.

METHODS

A single-center retrospective review was conducted of all elective open (oAAA) and endovascular (EVAR) AAA repairs (2010-20) to assess the incidence of and indications for repair of aneurysms below diameter recommendations (defined as <5.5cm in men and <5.0cm in women). Reasons for these repairs were defined as: 1) iliac aneurysm, 2) saccular morphology, 3) rapid expansion, 4) patient anxiety, 5) distal embolization, 6) other, and 7) no documented reason. The Vascular Quality Initiative (VQI) was queried for all asymptomatic oAAA and EVAR (2010-20) and repairs below diameter recommendations were identified. Findings from the single-center analysis were applied to the VQI cohort to extrapolate estimates of reasons for repairs done nationally. In-hospital mortality and major adverse cardiac events (MACE) were compared between those below size recommendations and those meeting size recommendations.

RESULTS

Of 456 elective AAA repairs at our center, 147 (32%) were below size recommendations. This was more common for EVAR (35% vs 28%). Reasons were: not documented (41%), iliac aneurysm (23%), saccular (10%), rapid expansion (10%), patient anxiety (7%), other (6%), and distal embolism (3%). Of 44,820 elective AAA repairs in VQI, 17,057 (38%) were below size recommendations (40% EVAR, 26% oAAA). Patients who were repaired below size recommendations had lower in-hospital death (oAAA: 2.4% vs 4.6% p<0.0001; EVAR: 0.3% vs 0.8% p<0.0001). When single-center findings were applied to the VQI dataset, an estimated 10,064 repairs were performed nationally for acceptable indications other than size criteria. Conversely, there may have been 6993 repairs (with an associated 35 deaths) performed without documented indication.

CONCLUSION

Repairs for AAA below recommended diameter guidelines account for approximately one third of all elective AAA procedures in both VQI and our single-center experience. Assuming our practice is typical, nearly 60% of repairs below size recommendations meet criteria for other clear reasons. The remaining 40% lack a documented reason, meaning 13% of all elective AAA repairs were done for aneurysms below size recommendations without an acceptable indication. As awareness of overuse/underuse is heightened, these data help estimate the expected proportion of repairs for less common pathologies. They also provide a potential baseline data point for efforts at reducing overuse.

Midterm outcomes of aneurysm repair with the COOK Zenith Alpha abdominal endovascular graft

INTRODUCTION

Outcome reports after endovascular aneurysm repair (EVAR) using the low-profile Zenith Alpha Abdominal Endovascular grafts (COOK medical, Bjæverskov, Denmark) are sparse. We present results from a single-center cohort treated with the Zenith Alpha, from a period where the graft was the primary EVAR device choice. The aim of the study was to evaluate short- and midterm outcomes of patients treated with the Zenith Alpha.

METHODS

A retrospective single-center study was performed including all patients treated with the Zenith Alpha graft from October 1, 2015, to September 30, 2018. All patients underwent computed tomography angiography (CTA) imaging preoperatively as well as at three and 12 months postoperatively. Hereafter, patients were followed yearly with duplex ultrasound and clinical exams. Additional imaging was performed on indication. All CTAs were analyzed using three-dimensional reconstruction software (Aquarius, TeraRecon, Durham, NC, USA). Data was extracted from electronic charts according to a protocol that remained unchanged until the end of the study (December 31, 2020). The following outcomes were assessed according to SVS/ISCVS reporting criteria: aortic-related and all-cause mortality, re-interventions, instruction for use (IFU) violations, endoleaks (EL), and aneurysm shrinkage.

RESULTS

A total of 241 patients were treated with the Zenith Alpha, and 214 (89%) were asymptomatic repairs. Technical success was achieved in 238 (99%) patients. 157 (65%) patients received implantation outside IFU. The median hospital length of stay was two days [IQR 2-3 days]. The median clinical follow-up was 35.1 months [IQR 28.8-47.5 months]. The four-year Kaplan-Meier (KM) estimate of freedom from re-intervention was 66% (95% CI: 59-73). The main reasons for re-interventions were iliac limb stenosis and occlusion (n=30; 12%) and type 2 EL (n=13; 5%). Overall, significantly more patients with grafts implanted outside distal IFU developed type 1B ELs (T1BELs) (n=10/11; p=.009). Aneurysm sac shrinkage was observed in 48 (25%) patients one year postoperatively. KM estimates of freedom from aortic-related mortality was 99% (95% CI: 98-100) four years postoperatively.

CONCLUSIONS

EVAR with the Zenith Alpha shows acceptable freedom from aortic-related mortality up to four years postoperatively. The majority of patients were treated outside IFU, and significantly more T1BEL appeared in this subgroup of patients. The leading cause for re-intervention was impaired limb patency. The root cause for impaired limb patency requires further investigation.

Long-term implications of elective evar that is non-compliant with clinical practice guideline diameter thresholds

OBJECTIVE

Compliance with Society for Vascular Surgery (SVS) abdominal aortic aneurysm (AAA) clinical practice guideline (CPG)-diameter thresholds is variable for endovascular aneurysm repair (EVAR). To evaluate the implications and appropriateness of repairs that are noncompliant with current guidelines, we investigated the long-term outcomes, adherence to imaging follow-up, and associated health care costs in patients undergoing EVAR for AAA who do or do not meet recommended diameter thresholds.

METHODS

All patients receiving elective EVAR from 2003 to 2016 in the SVS Vascular Quality Initiative with linked Medicare claims were reviewed. Weekend procedures and isolated iliac aneurysms, as well as symptomatic and ruptured presentations, were excluded. Diameter thresholds for noncompliant repairs were defined as: men <55 mm; women <50 mm who did not have an iliac diameter ≥30 mm. We evaluated adherence to postoperative imaging surveillance, reimbursement amounts, reintervention, rupture, and all-cause mortality. We defined an EVAR quality metric as performance of the index procedure with freedom from conversion to open repair, 5-year rupture-free survival, and adherence to minimum imaging surveillance (at least one computed tomography scan documented between 6 and 24 months postoperatively).

RESULTS

Among 19,018 elective EVARs, 35% did not meet CPG diameter thresholds (26% within 5 mm of threshold). The rate of noncompliant repairs increased over time (24% in 2003 vs 36% in 2016; P < .001). Patients undergoing noncompliant repairs were younger, less likely to have multiple comorbidities, and more likely to receive EVAR with adherence to instructions for use criteria (89% vs 79%; P < .001). Patients undergoing noncompliant repairs had greater 5-year freedom from reintervention (86% vs 81%; P < .001), rupture-free survival (94% vs 92%; P = .01), and overall survival rates (71% vs 61%; P < .001) compared with repairs that complied with CPG diameter thresholds. Although noncompliant repairs had higher rates of 1-year imaging surveillance, overall differences were modest (68% vs 65%; P = .003). Importantly, for the entire cohort, follow-up imaging surveillance decreased over time (93% in 2003 vs 63% in 2014; P < .001). Notably, although noncompliant repairs had higher rates of achieving the composite quality metric compared with compliant repairs (43% vs 38%; P < .001), failure occurred with a significant majority of all repairs.

CONCLUSIONS

Compliance with SVS-endorsed CPG diameter thresholds for elective EVAR is poor, and rates of noncompliance are increasing. Noncompliant repairs appear to be offered more commonly to patients with fewer comorbidities and favorable anatomy, and these repairs are associated with improved rates of reintervention, rupture, and survival compared with procedures meeting CPG diameter thresholds. Importantly, noncompliant repairs fail to meet minimum quality standards in a majority of cases, which underscores the need for further policies to improve the overall quality and appropriateness of AAA care delivery nationally.

What factors counteract mid-term survival following endovascular repair of abdominal aortic aneurysms?

Introduction

Endovascular aortic aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA) is increasingly used, and has become the standard treatment option for AAA.

Aim

To evaluate the outcomes and predictors of survival of endovascular treatment of AAA in the short- and medium-term.

Material and methods

A total of 222 patients having endovascular AAA repair between January 2013 and December 2019 by the same surgical team were included in the study. Patient demographics, perioperative and follow-up data including mortality, complications, and need for secondary intervention were collected. The primary endpoint was all-cause mortality. Kaplan-Meier analysis was conducted for survival and Cox regression models were assessed for predictors of survival.

Results

The median age was 70 years, with male predominance (202 patients, 91%). Thirty-day mortality was 1.8%. Median follow-up to the primary endpoint was 20 months (range: 1–80 months). Survival rates at 1, 3, and 5 years were 93.5%, 81.4%, and 62.2%, respectively. Freedom from secondary intervention rates were 95.5% at 1 year, 88.7% at 3 years, and 82.1% at 5 years. Cox proportional hazard models showed that preoperative creatinine levels ≥ 1.8 mg/dl (hazard ratio (HR) = 2.68, 95% CI: 1.21–6.42, p = 0.027), haemoglobin levels < 10 gr/dl (HR = 3.38, 95% CI: 1.16–9.90, p = 0.026), ejection fraction < 30% (HR = 5.67, 95% CI: 1.29–24.86, p = 0.021), and AAA diameter ≥ 6.0 cm (HR = 2.20, 95% CI: 1.01–4.81, p = 0.049) were independently associated with mid-term survival.

Conclusions

EVAR is a safe procedure with low postoperative morbidity and mortality. This study confirms that the mid-term survival and results are favourable. However, the analysed factors in this study that predict reduced survival (high preoperative creatinine, low haemoglobin, low ejection fraction and larger aneurysms) should be judged when planning endovascular repair of AAA.

Effect of Abdominal Aortic Aneurysm Size on Mid-Term Mortality After Endovascular Repair

BACKGROUND

Previous studies have suggested that large preoperative AAA size may impact late survival after elective EVAR. It is unclear, however, whether this association applies to patients with smaller AAA between 5.0-5.5 cm, who constitute a substantial portion of patients undergoing elective EVAR. The purpose of this study was to delineate the effect of AAA size between 5.0 and 5.5 cm on mid-term mortality after EVAR by analyzing a large national cohort, the Vascular Quality Initiative (VQI) database.

METHODS

Using the Vascular Quality Initiative (VQI) national database, patients who underwent EVAR for intact AAA between 2003 and 2018 were identified and stratified based on maximal AAA diameter into 3 groups: Group 1 (4.0 cm ≤ AAA <5.0 cm); Group 2 (5.0 cm ≤ AAA < 5.5 cm); and Group 3 (AAA ≥ 5.5 cm). Cox proportional hazard model and propensity score matching method were used to estimate AAA size effect on all-cause mortality at 1, 3, and 5 years after EVAR while adjusting for potential confounders.

RESULTS

The study included 32,398 patients, of whom 81% were men with a mean age of 74. The most common group who underwent EVAR was Group 2 (5.0 cm ≤ AAA < 5.5 cm). Larger AAA size was associated with male sex (75% versus 79% versus 84%, for Groups 1, 2, and 3 respectively; P < 0.0001) and with coronary artery disease (27% versus 29% versus 31%, for Groups 1, 2, and 3 respectively, P< 0.0001); but was negatively associated with active smoking (33% versus 31% versus 30%, for Groups 1, 2, and 3, respectively, P< 0.001). While 10% of the largest and smallest AAA groups (Groups 3 and 1, respectively) were symptomatic, only 5% of patients in Group 2 were symptomatic (P < 0.01). Adjusted Cox proportional hazard modeling revealed that patients in Group 2 were at significantly lower risk of 5-year mortality when compared to patients in Group 3 (HR 0.66, 95% CI 0.61-0.72, P< 0.01), while similar in risk when compared to patients in Group 1 (HR 1.11, 95% CI 0.93-1.32, P= 0.26).

CONCLUSION

Our analysis found that over 40% of EVAR in the national VQI cohort were performed for AAA < 5.5 cm, with the greatest number of patients undergoing EVAR at AAA size 5.0-5.5cm. Patients with AAA size 5.0-5.5 cm had better 5-year survival outcomes than patients with AAA ≥ 5.5 cm, and similar survival to patients with small AAA between 4.0-5.0 cm.

The Effect of Abdominal Aortic Aneurysm Size on Endoleak, Secondary Intervention and Overall Survival Following Endovascular Aortic Aneurysm Repair

OBJECTIVE

The purpose of this study was to identify the effect of abdominal aortic aneurysm (AAA) size on endoleak development and secondary intervention after endovascular repair (EVAR), as well as to examine the effect on overall survival and cause of mortality.

METHODS

Retrospective analysis was performed on all non-ruptured AAA treated by elective EVAR using FDA-approved endografts in our facility from July 2004 to December 2017. Patients were grouped into 3 cohorts based on preoperative aneurysm size: Group I (<5.5 cm), Group II (5.5-6.4 cm), and Group III (≥ 6.5 cm). Occurrences of endoleak, secondary intervention and overall survival underwent univariate and multivariate analysis. Cause of death data on deceased patients was similarly examined.

RESULTS

A total of 517 patients were analyzed. There was no difference between size groups in the rate of endoleak (Group I 48/277, 17.3%; Group II 33/160, 20.6%; Group III 18/80, 22.5%; p = 0.46) or time until endoleak development. Univariate analysis showed no difference in the rate of secondary intervention (Group I 36/277, 13.0%; Group II 24/160, 15.0%; Group III 18/80, 22.5%; p = 0.11), time until intervention or number of interventions performed. Multivariate analysis showed an association with shorter time to secondary intervention for both Group III aneurysms (HR 2.03, 95% CI 1.11-3.73; p = 0.02) and female patients (HR 1.79, 95% CI 1.02-3.13; p = 0.04). There was no difference in overall survival, aneurysm-related mortality or overall cause of mortality.

CONCLUSION

AAA diameter prior to EVAR was not associated with any differences in rates of endoleak or secondary intervention, and was not associated with poorer overall survival or greater aneurysm-related mortality. Patients with suitable anatomy for EVAR can be considered for this intervention without concern for increased complications or poorer outcomes related to large aneurysm diameter alone.

Late outcomes after endovascular and open repair of large abdominal aortic aneurysms

OBJECTIVE

The risk of aortic abdominal aneurysm (AAA) rupture increases with an increasing aneurysm diameter. However, the effect of the AAA diameter on late outcomes after aneurysm repair is unclear. Therefore, we assessed the association of a large AAA diameter with late outcomes for patients undergoing open and endovascular AAA repair.

METHODS

We identified all patients who had undergone elective open or endovascular infrarenal aneurysm repair from 2003 to 2016 in the Vascular Quality Initiative linked to Medicare claims for long-term outcomes. A large AAA diameter was defined as a diameter >65 mm. We assessed the 5-year reintervention, rupture, mortality, and follow-up rates. We constructed propensity scores and used inverse probability-weighted Kaplan-Meier estimations and Cox proportional hazard models to identify independent associations between large AAA repair and our outcomes.

RESULTS

Of the 21,119 aneurysm repairs identified, 15.2% were for large AAAs. Of the 21,119 repairs, 19,017 were endovascular and 2102 were open. The large AAA cohort was less likely to have undergone endovascular aneurysm repair (EVAR; 84.9% vs 91%; P < .001), more likely to be older (median age, 76 vs 75 years; P < .001), and were less likely to be women (16.2% vs 21.7%; P < .001). After EVAR, patients with large AAAs had had lower adjusted 5-year freedom from reintervention (73.9% vs 84.6%; P < .001), freedom from rupture (88.5% vs 93.6%; P < .001), survival (58.0% vs 66.4%; P < .001), and freedom from loss to follow-up (77.7% vs 83.3%; P < .001) compared with patients with smaller AAAs. However, after open repair, the adjusted 5-year freedom from reintervention (95.8% vs 93.3%; P = .11), freedom from rupture (97.4% vs 97.8%; P = .32), survival (70.4% vs 74.0%; P = .13), and loss to follow-up (60.5% vs 62.8%; P = .86) were similar to the results for patients with smaller AAAs. For patients with large AAAs, the adjusted 5-year survival was lower after EVAR than that after open repair (55.3% vs 63.7%) but not after smaller AAA repair (67.3% vs 70.6%).

CONCLUSION

The 5-year adjusted reintervention, ruptures, mortality, and loss to follow-up rates for patients who had undergone large AAA EVAR were higher than those for patients who had undergone small AAA EVAR and large AAA open repair. Therefore, for patients with large AAAs who are medically fit, open repair should be strongly considered. Furthermore, these findings highlight the necessity for rigorous long-term follow-up after EVAR.

Regional Market Competition is Associated with Aneurysm Diameter at the Time of EVAR

BACKGROUND

Local market competition has been previously associated with more aggressive surgical decision-making. For example, more local competition for organs is associated with acceptance of lower quality kidney offers in transplant surgery. We hypothesized that market competition would be associated with the size of an abdominal aortic aneurysm (AAA) at the time of elective endovascular aneurysm repair (EVAR).

METHODS

We included all elective EVARs reported in the Vascular Quality Initiative database (2012-2018). Small AAAs were defined as a maximum diameter <5.5 cm in men or <5.0 cm in women. We calculated the Herfindahl-Hirschman Index (HHI), a measure of physician market concentration (higher HHI = less market competition), for each US census region. Multilevel regression was used to examine the association between the size of AAA at EVAR and HHI, clustering by region.

RESULTS

Of 37,914 EVARs performed, 15,379 (40.6%) were for small AAAs. There was significant variation in proportion of EVARs performed for small AAAs across regions (P < 0.001). The South had both the highest proportion of EVARs for small AAAs (44.2%) as well as the highest market competition (HHI 50), whereas the West had the lowest proportion of EVARs for small AAAs (35.0%) and the lowest market competition (HHI 107). Adjusting for patient characteristics, each 10 unit increase in HHI was associated with a 0.1 mm larger maximum AAA diameter at the time of EVAR (95% CI 0.04-0.24 mm, P = 0.005).

CONCLUSIONS

Physician market concentration is independently associated with AAA diameter at time of elective EVAR. These data suggest that physician decision-making for EVAR is impacted by market competition.

Infrarenal Abdominal Aortic Aneurysm Endovascular Treatment: Long-term Results From a Single-Center Experience in an Unselected Patient Population

BACKGROUND

The aim of the present study was to evaluate early-, mid-, and long-term outcomes in an unselected population of patients treated for abdominal aortic aneurysms (AAAs) by endovascular aneurysm repair (EVAR) with different commercially available off-the-shelf devices.

MATERIALS AND METHODS

A retrospective study was conducted on a prospectively compiled computerized database on patients presenting an infrarenal AAA treated between January 2008 and December 2015 in a high-volume Italian tertiary referral Center. Demographic, clinical, and specific morphological features were considered as potentially influencing the outcomes and the type of the implanted device. Outcome measures were procedure-related reintervention, AAA-related, and all-cause mortality rates at 30-day, 12-month, and long-term follow-up. Reinterventions considered for the analysis were AAA rupture, graft infection, type I or III endoleaks, type II endoleaks with sac enlargement > 5 mm, graft stenosis or occlusions, procedures related to renal or visceral ischemia, and reintervention for access vessel injury.

RESULTS

Of 498 EVAR procedures performed for elective infrarenal AAA treatment during the entire study period, 479 patients were enrolled, the mean age was 73.5 ± 7.34 years (range 51-91), and 416 (86.84%) were men. The mean maximum AAA diameter was 52.02 ± 8.04 mm (range 39-90.2), a maximum AAA diameter ≥59 mm was recorded in 107 patients (22.33%), and an aortic neck length was <10 mm in 137 (28.60%). Technical success was achieved in all patients. At a mean follow-up of 52.97 ± 26.16 months (range 1-120), overall reintervention and death rates were 8.14% and 20.04%, respectively, without AAA-related deaths. At univariate analysis, hypertension was the only demographical variable found to be associated with higher risk of reintervention, P = 0.04 (OR: 2.34; CI 95%: 1.00-5.42). Furthermore, male sex (P = 0.02; OR: 2.62; CI 95%: 1.09-6.27) and chronic renal insufficiency (P = 0.003; OR: 2.08; CI 95%: 1.27-3.42) were associated with higher mortality rates. AAA diameter ≥59 mm was statistically associated with a higher rate of both reintervention and mortality: P < 0.001 (OR: 9.05; CI 95%: 4.52-18.11) and <0.001 (4.00; 2.46-6.49), respectively.

CONCLUSIONS

Our experience seems to suggest that EVAR could be safely and effectively performed in an unselected patients' population, with encouraging results up to a ten-year follow-up.