Improved Outcomes for Ruptured Abdominal Aortic Aneurysm Through Centralisation

Temporal Trends and Outcomes of Abdominal Aortic Aneurysm Care in the United States

BACKGROUND

Endovascular aortic aneurysm repair (EVAR) has had a dynamic impact on abdominal aortic aneurysm (AAA) care, often supplanting open AAA repair (OAR). Accordingly, US AAA management is often highlighted by disparities in patient selection and guideline compliance. The purpose of this analysis was to define secular trends in AAA care.

METHODS

The Society for Vascular Surgery Vascular Quality Initiative was queried for all EVARs and OARs (2011-2021). End points included procedure utilization, change in mortality, patient risk profile, Society for Vascular Surgery-endorsed diameter compliance, off-label EVAR use, cross-clamp location, blood loss, in-hospital complications, and post-EVAR surveillance missingness. Linear regression was used without risk adjustment for all end points except for mortality and complications, for which logistic regression with risk adjustment was used.

RESULTS

In all, 66 609 EVARs (elective, 85% [n=55 805] and nonelective, 15% [n=9976]) and 13 818 OARs (elective, 70% [n=9706] and nonelective, 30% [n=4081]) were analyzed. Elective EVAR:OAR ratios were increased (0.2 per year [95% CI, 0.01-0.32]), while nonelective ratios were unchanged. Elective diameter threshold noncompliance decreased for OAR (24%→17%; P=0.01) but not EVAR (mean, 37%). Low-risk patients increasingly underwent elective repairs (EVAR, +0.4%per year [95% CI, 0.2-0.6]; OAR, +0.6 points per year [95% CI, 0.2-1.0]). Off-label EVAR frequency was unchanged (mean, 39%) but intraoperative complications decreased (0.5% per year [95% CI, 0.2-0.9]). OAR complexity increased reflecting greater suprarenal cross-clamp rates (0.4% per year [95% CI, 0.1-0.8]) and blood loss (33 mL/y [95% CI, 19-47]). In-hospital complications decreased for elective (0.7% per year [95% CI, 0.4-0.9]) and nonelective EVAR (1.7% per year [95% CI, 1.1-2.3]) but not OAR (mean, 42%). A 30-day mortality was unchanged for both elective OAR (mean, 4%) and EVAR (mean, 1%). Among nonelective OARs, an increase in both 30-day (0.8% per year [95% CI, 0.1-1.5]) and 1-year mortality (0.8% per year [95% CI, 0.3-1.6]) was observed. Postoperative EVAR surveillance acquisition decreased (67%→49%), while 1-year mortality among patients without imaging was 4-fold greater (9.2% versus imaging, 2.0%; odds ratio, 4.1 [95% CI, 3.8-4.3]; P<0.0001).

CONCLUSIONS

There has been an increase in EVAR and a corresponding reduction in OAR across the United States, despite established concerns surrounding guideline adherence, reintervention, follow-up, and cost. Although EVAR morbidity has declined, OAR complication rates remain unchanged and unexpectedly high. Opportunities remain for improving AAA care delivery, patient and procedure selection, guideline compliance, and surveillance.

Center Volume and Failure to Rescue after Open or Endovascular Repair of Ruptured Abdominal Aortic Aneurysms

BACKGROUND

The correlation between center volume and elective abdominal aortic aneurysm(AAA) repair outcomes is well established; however, these effects for either endovascular(EVAR) or open(OAR) repair of ruptured AAA(rAAA) remains unclear. Notably, the capacity to either avert or manage complications associated with postoperative mortality is an important cause of outcome disparities following elective procedures; however, there is a paucity of data surrounding non-elective presentations. Therefore, the purpose of this analysis was to describe the association between annual center volume, complications, and failure to rescue(FtR) after EVAR and OAR of rAAA.

METHODS

All consecutive endovascular and open rAAA repairs from 2010-2020 in the Vascular Quality Initiative were examined. Annual center volume(procedures/year per center) was grouped into quartiles: EVAR-Q1[<14](3.4%), Q2[14-23](12.8%), Q3[24-37](24.7%), Q4[>38](59.1%); OAR-Q1[<3](5.4%), Q2[4-6](12.8%), Q3[7-10](22.7%), Q4[>10](59.1%). The primary end-point was FtR, defined as in-hospital death after experiencing one of six major complications(cardiac, renal, respiratory, stroke, bleeding, colonic ischemia). Risk-adjusted analyses for inter-group comparisons was completed using multivariable logistic regression.

RESULTS

The unadjusted in-hospital death rate was 16.5% and 28.9% for EVAR and OAR, respectively. Complications occurred in 45% of EVAR(n=1,439/3,188) and 70% of OAR(n=1,366/1,961) patients with corresponding FtR rates of 14%(EVAR) and 26%(OAR). For OAR, Q4-centers had a 43% lower FtR risk(OR 0.57, 95%CI 0.4-0.9;p=.017) compared to Q1 centers. Centers performing >5 OARs/year had a 43% lower risk(OR 0.57, 95%CI 0.4-0.7;p<.001) of FtR and this decreased 4% for each additional 5 procedures performed annually(95%CI .93-.991;p=.013). However, there was no significant relationship between center volume and FtR after EVAR. The risk of FtR was strongly associated with a greater number of complications for both procedures(OR multiplied by 6.5 for EVAR and 1.5 for OAR for each additional complication;p<.0001). Among OAR patients with a single recorded complication, return to the operating room for bleeding had highest risk of in-hospital mortality(OR 4.1, 95%CI 1.1-4.8;p=.034), while no specific type of complication increased FtR risk after EVAR.

CONCLUSIONS

FtR occurs commonly after EVAR and OAR of rAAA within VQI centers. Importantly, increasing center volume was associated with reduced FtR risk after OAR but not EVAR. Complication pattern and frequency predicted FTR after either repair strategy. For stable patients, especially those deemed anatomically ineligible for EVAR, these findings emphasize the need to improve coordination of regional referral networks that centralize rAAAs to high-volume centers. Moreover, hospitals that treat rAAA should invest resources that develop protocols targeting specific complications to mitigate risk of preventable postoperative death.

Induction of CD73 prevents death after emergency open aortic surgery for a ruptured abdominal aortic aneurysm: a randomized, double-blind, placebo-controlled study

Mortality remains high after emergency open surgery for a ruptured abdominal aortic aneurysm (RAAA). The aim of the present study was to assess, if intravenous (IV) Interferon (IFN) beta-1a improve survival after surgery by up-regulating Cluster of differentiation (CD73). This is a multi-center phase II double-blind, 2:1 randomized, parallel group comparison of the efficacy and safety of IV IFN beta-1a vs. placebo for the prevention of death after open surgery for an infra-renal RAAA. All study patients presented a confirmed infra-renal RAAA, survived the primary emergency surgery and were treated with IFN beta-1a (10 μg) or matching placebo for 6 days after surgery. Major exclusion criteria included fatal hemorrhagic shock, chronic renal replacement therapy, diagnosed liver cirrhosis, severe congestive heart failure, advanced malignant disease, primary attempt of endovascular aortic repair (EVAR), and per-operative suprarenal clamping over 30 min. Main outcome measure was all-cause mortality at day 30 (D30) from initial emergency aortic reconstruction. The study was pre-maturely stopped due to a reported drug-drug interaction and was left under-powered. Out of 40 randomized patients 38 were included in the outcome analyses (27 IFN beta-1a and 11 placebo). There was no statistically significant difference between treatment groups at baseline except more open-abdomen and intestinal ischemia was present in the IFN beta-1a arm. D30 all-cause mortality was 22.2% (6/27) in the IFN beta-1a arm and 18.2% (2/11) in the placebo arm (OR 1.30; 95% CI 0.21-8.19). The most common adverse event relating to the IFN beta-1a was pyrexia (20.7% in the IFN beta-1a arm vs. 9.1% in the placebo arm). Patients with high level of serum CD73 associated with survival (P = 0.001) whereas the use of glucocorticoids and the presence of IFN beta-1a neutralizing antibodies associated with a poor CD73 response and survival. The initial aim of the trial, if postoperative INF beta-1a treatment results on better RAAA survival, could not be demonstrated. Nonetheless the anticipated target mechanism up-regulation of CD73 was associated with 100% survival. According to present results the INF beta-1a induced up-regulation of serum CD73 was blocked with both use of glucocorticoids and serum IFN beta-1a neutralizing antibodies. The study was pre-maturely stopped due to interim analysis after a study concerning the use if IV IFN beta-1a in ARDS suggested that the concomitant use of glucocorticoids and IFN beta-1a block the CD73 induction. Trial registration: ClinicalTrials.gov NCT03119701. Registered 19/04/2017 (retrospectively registered).

Epidemiology of abdominal aortic aneurysms

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

Nationwide Analysis of Ruptured Abdominal Aortic Aneurysm in Portugal (2000-2015)

OBJECTIVE

Ruptured abdominal aortic aneurysm (rAAA) is a lethal condition that requires acute repair to prevent death. This analysis aims to assess the nationwide trends in rAAA admission, repair and mortality in a country, Portugal, without national screening for AAA.

METHODS

rAAA registered in the hospital administrative database of the National Health Service and all nationally registered deaths due to rAAA based on death certificate data were analysed. Three time periods (2000-2004, 2005-2009, and 2010-2015) were compared in patients ≥ 50 years old to assess the variations over time.

RESULTS

A total of 2 275 patients ≥50 years old with rAAA were identified in the two databases from 2000 to 2015. The age standardised incidence of rAAA was 2.78 ± 0.24/100 000/year in 2000-2004, 3.17 ± 0.39/100 000/year in 2005-2009 and 3.21 ± 0.28/100 000/year in 2010-2015 (p < .001). When comparing the time periods 2000-2004 to 2005-2009, the age standardised rate of admission (n = 1460) increased from 1.57 ± 0.25/100 000/year to 2.24 ± 0.32/100 000/year (p < .001). The operative mortality rates decreased during this time period (from 55.3 ± 4.7% to 48.8 ± 4.7%, p < .001). In 2010-2015, the age standardised rate of admissions due to rAAA decreased (1.98 ± 0.22/100 000/year). Operative mortality remained stable (48.9 ± 6.2%). The rate of patient deaths outside the hospital decreased from the first to the second period (1.21 ± 0.10/100 000/year and 0.93 ± 0.29/100 000/year, respectively) but later increased (1.14 ± 0.22/100 000/year). This resulted in a higher overall rAAA related mortality in Portugal in the third period (2.20 ± 0.18/100 000/year, 2.21 ± 0.27/100 000/year and 2.26 ± 0.26/100 000/year in 2000-2004, 2005-2009, and 2010-2015, respectively, p < .001).

CONCLUSION

Overall, the incidence of rAAA in Portugal has been stable over the past 10 years. The rates of admission, repair, and death due to rAAA repair seem to have reached an inflection point and are now decreasing. Mortality outside the hospital remains a matter of concern, warranting further planning of streamlined transfer networks and vascular surgical departments.

Expanded Suitability of Ruptured Abdominal Aortic Aneurysms for Total Endovascular Repair Using the Endurant Endograft and Heli-FX EndoAnchors

Purpose: To assess if the suitability of endovascular aneurysm repair (EVAR) of ruptured abdominal aortic aneurysms (RAAAs) can be expanded by combining the Endurant stent-graft with the Heli-FX EndoAnchors. Materials and Methods: Contrast-enhanced computed tomography (CT) scans of 90 patients (mean age 73.2±9 years; 87 men) with RAAA admitted between January 2014 and January 2018 in 2 tertiary care centers were analyzed in a 3-dimensional workstation. Anatomical features of the aneurysms according to the instructions for use (IFU) for the Endurant endograft were evaluated and expansion of treatment with Heli-FX EndoAnchors was assessed. Results: Neck length <10 mm was present in 41 (45.6%) patients; 5 had neck diameters outside the IFU and 45 (50.0%) had conical necks. Thrombus and calcium were absent in 63 (70.0%) and 73 (81.1%), respectively. In the study cohort, 44 (48.9%) patients met all the neck criteria, although overall IFU compliance was found in only 35 (38.9%) patients due to iliac-related issues in 21 patients. The adjunctive use of EndoAnchors in the entire study group would enhance the therapeutic range to an additional 24 patients, 8 of whom would need an associated iliac procedure. This represents an expansion of the total EVAR approach from 48.9% to 75.6% of cases if some iliac issues are overcome and from 38.9% to 56.7% without correcting iliac deficiencies. Conclusion: The main reason of being unfit for endovascular treatment in this series was neck length <10 mm. Based on this analysis, nearly 40% of RAAA patients would have been candidates for EVAR based on the IFU neck criteria for the Endurant stent-graft. This suitability could be nearly doubled with the use of EndoAnchors and correction of unsuitable iliac anatomy. The use of EndoAnchors has the potential to offer a significant benefit in the endovascular treatment of RAAA patients.