Paradigm shifts in abdominal aortic aneurysm management based on vascular registries

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.

Endovascular aneurysm repair under local anesthesia through bilateral percutaneous femoral access is a safe strategy to improve early outcomes and reduce hospital stay

BACKGROUND

To estimate the impact of anesthetic conduct, alone and in combination with the type of femoral access, on early results after endovascular aneurysm repair (EVAR).

METHODS

A retrospective multicenter analysis on patients undergoing elective standard EVAR at four academic centers was performed. Patients undergoing the procedure through either local or general anesthesia were compared. Comparative subanalyses of the two groups were performed for the type of femoral access to evaluate further impact on outcomes.

RESULTS

Five hundred twenty-four patients underwent elective standard EVAR, of which 207 (39.5%) under general anesthesia and 317 (60.5%) under local anesthesia. Patients who underwent general anesthesia had higher 30-day mortality rates (3.4% vs. 0.3%, P=0.005), as well as slightly worse 30-day major systemic complication rates (8.2% vs. 5.4%, P=0.195). There were no differences in terms of reinterventions (2.1% vs. 2.5%, P=0.768) and aneurysm-related mortality (0% vs. 0.4%, P=0.422) at one year. Total intervention times were significantly longer in the general anesthesia group (126 vs. 89 minutes, P=0.001), as well as the total length of hospital stay (7.6 vs. 5.3 days, P=0.007). At subanalyses, the combination of local anesthesia with bilateral percutaneous femoral access further improved 30-day outcomes and determined an additional reduction in total intervention times and ICU stays.

CONCLUSIONS

EVAR performed under local anesthesia has a significantly better impact on early results when compared to general anesthesia. Combining percutaneous bilateral femoral access to local anesthesia reduced procedural times, ICU stays and consequently improved early results.

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.

Abdominal Aortic Aneurysm Repair in Patients with Concomitant Cancer: A Literature Review

OBJECTIVES

Abdominal aortic aneurysmal (AAA) repair in patients with concomitant cancer is controversial due to increased comorbidity and reduced life expectancy in this specific patient group. This literature review aims to investigate the evidence supporting one treatment modality over another (endovascular aortic repair (EVAR) or open repair (OR)), as well as treatment strategy (staged AAA-, cancer first or simultaneous procedures) in patients with AAA and concomitant cancer.

METHODS

Literature review, including studies published from 2000 to 2021 on surgical treatment in patients with AAA and concomitant cancer and related outcomes (30-day morbidity/complications as well as 30-day and 3-year mortality).

RESULTS

24 studies comprising 560 patients undergoing surgical treatment of AAA and concomitant cancer were included. Of these, 220 cases were treated with EVAR and 340 with OR. Simultaneous procedures were performed in 190 cases, 370 received staged procedures. The 30-day mortality for EVAR versus OR was 1% and 8%, corresponding to a relative risk (RR) of 0.11 (95% CI: 0.03-0.46, p = 0.002). No difference in mortality was observed between staged versus simultaneous procedure nor between AAA-first versus cancer-first strategy, RR 0.59 (95% CI: 0.29-1.1, p = 0.13) and 0.88 (95% CI 0.34-2.31, p = 0.80), respectively. Overall, 3-year mortality was 21% for EVAR and 39% for OR from 2000-2021, while the mortality up to 3 years after EVAR within recent years (2015-2021) was 16%.

CONCLUSION

This review supports EVAR treatment as first choice if suitable. No consensus was established on treating either the aneurysm or the cancer first or simultaneously. Long-term mortality after EVAR was comparable to non-cancer patients within recent years.

Capturing the Complexity of Open Abdominal Aortic Surgery in the Endovascular Era

OBJECTIVE

Volume and quality benchmarks for open abdominal aortic surgery and particularly open aortic aneurysm repair (OAR) in the endovascular era are guided by the Society for Vascular Surgery (SVS) guidelines, but the Vascular Quality Initiative (VQI) OAR module fails to capture the full spectrum of complex OAR. We hypothesized that VQI-ineligible complex OAR is the dominant form of open repairs performed at a VQI-participating tertiary center.

METHODS

All OAR cases performed at a single tertiary care center from 2007 to 2020 were reviewed. The VQI OAR criteria were applied with exclusions (non-VQI) defined as concomitant renal bypass, clamping above the superior mesenteric artery (SMA) or celiac artery, repairs performed for trauma, anastomotic aneurysm, isolated iliac aneurysm, or infected aneurysms. Linear regression was used to assess temporal trends.

RESULTS

Among a total of 481 open abdominal aortic operations, 355 (74%) were OAR. The average annual OAR volume remained stable over 14 years (25 ± 6; P = .46). Non-VQI OAR comprised 54% of all cases and persisted over time (R² = .047, P = .46). Supra-celiac clamping (35%) was often necessary. The proportion of endograft explantation cases significantly increased over time from 4% in 2007 to 20% in 2019 (P = .01). Infectious indications represented 20% (n = 70) of cases. Visceral branch grafts were performed in 16% of all cases. OAR for ruptured aneurysm constituted 10% of cases. Thirty-day mortality was significantly higher in non-VQI vs. VQI-eligible OAR cases (10% vs. 4%; P = .04).

CONCLUSIONS

Complex OAR comprises a majority of OAR cases in a contemporary tertiary referral hospital, yet these cases are not accounted for in the VQI. Creation of a "complex OAR" VQI module would capture these cases in a quality-driven national registry and help to better inform benchmarks for volume and outcomes in aortic surgery.

Association of Hospital Volume with Perioperative Mortality of Endovascular Repair of Complex Aortic Aneurysms: A Nationwide Cohort Study

OBJECTIVE

We evaluate nationwide perioperative outcomes of complex EVAR and assess the volume-outcome association of complex EVAR.

SUMMARY OF BACKGROUND DATA

Endovascular treatment with fenestrated (FEVAR) or branched (BEVAR) endografts is progressively used for excluding complex aortic aneurysms (complex AAs). It is unclear if a volume-outcome association exists in endovascular treatment of complex AAs (complex EVAR).

METHODS

All patients prospectively registered in the Dutch Surgical Aneurysm Audit who underwent complex EVAR (FEVAR or BEVAR) between January 2016 and January 2020 were included. The effect of annual hospital volume on perioperative mortality was examined using multivariable logistic regression analyses. Patients were stratified into quartiles based on annual hospital volume to determine hospital volume categories.

RESULTS

We included 694 patients (539 FEVAR patients, 155 BEVAR patients). Perioperative mortality following FEVAR was 4.5% and 5.2% following BEVAR. Postoperative complication rates were 30.1% and 48.7%, respectively. The first quartile hospitals performed <9 procedures/yr; second, third, and fourth quartile hospitals performed 9-12, 13-22, and ≥23 procedures/yr. The highest volume hospitals treated the significantly more complex patients. Perioperative mortality of complex EVAR was 9.1% in hospitals with a volume of < 9, and 2.5% in hospitals with a volume of ≥13 (P = 0.008). After adjustment for confounders, an annual volume of ≥13 was associated with less perioperative mortality compared to hospitals with a volume of < 9.

CONCLUSIONS

Data from this nationwide mandatory quality registry shows a significant effect of hospital volume on perioperative mortality following complex EVAR, with high volume complex EVAR centers demonstrating lower mortality rates.