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

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-First Strategy for Ruptured Abdominal Aortic Aneurysm Might Not Be Applicable to all Cases

BACKGROUND

We evaluate the relationship between the hospital case volume (HCV) and mortality outcomes after open aortic repair (OAR) and endovascular aortic repair (EVAR) of intact (iEVAR) and ruptured (rEVAR) abdominal aortic aneurysm (AAA) using a contemporary administrative database.

METHODS

The Healthcare Cost and Utilization Project Database for New York (2016) and New Jersey/Maryland/Florida (2016-2017) were queried using International Classification of Disease-10th edition to identify patients who had undergone OAR and EVAR. The hospitals were categorized into quartiles (Q) per overall (EVAR + OAR) volume, OAR-alone volume and EVAR-alone volume. Cox regression adjusted for confounding factors was used to estimate hazard ratios (HRs) for mortality.

RESULTS

A total of 8,825 patients (mean age, 73.5 ± 9.5 years; 6,861 male [77.7%]) had undergone 1,355 OARs and 7,470 EVARs. Overall HCV had no impact on in-hospital mortality across quartiles after (iEVAR) (range, 0.7%-1.4%, P = 0.15), (rEVAR) (range, 20.5%-29.6%, P = 0.63) and open repair of intact AAA (iOAR) (range, 4.9%-8.8%, P = 0.63). However, the mortality rates after open repair of ruptured AAA (rOAR) in highest-volume (Q4) hospitals were significantly lower than those in the 3 lower quartile hospitals (23.1% vs. 44.7%, P < 0.001). When analyzed per OAR-alone volume, the same findings were observed (22.0% for Q4 vs. 41.6% for Q1-3, P < 0.001). Furthermore, in Q4 hospitals per the OAR-alone volume analysis, the mortality hazard was greater for rEVAR (39.0%) than for rOAR (22.0%) (HR = 2.3, 95% confidence interval, 1.02-5.34, P < 0.05).

CONCLUSIONS

The mortality rates for iEVAR, rEVAR and iOAR were independent of HCV. However, after rOAR, mortality rates in high OAR volume hospitals were lower than those in the lower quartile hospitals, and, at least comparable to those of rEVAR. EVAR-first strategy for ruptured AAA might not be applicable to all cases. Patent-specific, individualized treatment should be the gold standard. For patients requiring rOAR, transfer to a regional center of excellence, when clinical safe, should be encouraged.

Variability in short-term mortality following repair of ruptured abdominal aortic aneurysms across centers and physicians

BACKGROUND

Variation in the care management of repairs for ruptured infrarenal abdominal aortic aneurysms between centers and physicians, such as procedural volumes, may explain differences in mortality outcomes. First, we quantified the center and physician variability associated with 30- and 90-day mortality risk after ruptured open surgical repair (rOSR) and ruptured endovascular aneurysm repair (rEVAR). Second, we explored wheter part of this variability was attributable to procedural volume at the center and physician levels.

METHODS

Two cohorts including rOSR and rEVAR procedures between 2013 and 2019 were analyzed from the Vascular Quality Initiative database. Thirty- and 90-day all-cause mortality rates were derived from linked Medicare claims data. The median odds ratio (MOR) (median mortality risk from low- to high-risk cluster) and intraclass correlation coefficient (ICC) (variability attributable to each cluster) for 30- and 90-day mortality risks associated with center and physician variability were derived using patient-level adjusted multilevel logistic regression models. Procedural volume was calculated at the center and physician levels and stratified by quartiles. The models were sequentially adjusted for volumes, and the difference in ICCs (without vs with accounting for volume) was calculated to describe the center and physician variability in mortality risk attributable to volumes.

RESULTS

We included 450 rOSRs (mean age, 74.5 ± 7.6 years; 23.5% female) and 752 rEVARs (76.4 ± 8.4 years; 26.1% female). After rOSRs, the 30- and 90-day mortality rates were 32.9% and 38.7%, respectively. No variability across centers and physicians was noted (30- and 90-day MORs ≈1 and ICCs ≈0%). Neither center nor physician volume was associated with 30-day (P = .477 and P = .796) or 90-day mortality (P = .098 and P = .559). After rEVAR, the 30- and 90-day mortality rates were 21.3% and 25.5%, respectively. Significant center variability (30-day MOR, 1.82 [95% confidence interval (CI), 1.33-2.22]; ICC, 11% [95% CI, 2%-36%]; and 90-day MOR, 1.76 [95% CI, 1.37-2.09]; ICC, 10% [95% CI, 3%-30%]), but negligeable variability across physicians (30- and 90-day MORs ≈1 and ICCs ≈0%) were noted. Neither center nor physician volume were associated with 30-day (P = .076 and P = .336) or 90-day mortality risk (P = .066 and P = .584). The center variability attributable to procedural volumes was negligeable (difference in ICCs, 1% for 30-day mortality; 0% for 90-day mortality).

CONCLUSIONS

Variability in practice from center to center was associated with short-term mortality outcomes in rEVAR, but not for rOSR. Physician variability was not associated with short-term mortality for rOSR or rEVAR. Annualized center and physician volumes did not significantly explain these associations. Further work is needed to identify center-level factors affecting the quality of care and outcomes for ruptured abdominal aortic aneurysms.

Modern management of ruptured abdominal aortic aneurysm

Ruptured abdominal aortic aneurysms (rAAA) remain one of the most clinically challenging and technically complex emergencies in contemporary vascular surgery practice. Over the past 30 years, a variety of changes surrounding the treatment of rAAA have evolved including improvements in diagnosis, development of coordinated referral networks to transfer patients more efficiently to higher volume centers, deliberate de-escalation of pre-hospital resuscitation, modification of patient and procedure selection, implementation of clinical pathways, as well as enhanced awareness of certain high-impact postoperative complications. Despite these advances, current postoperative outcomes remain sobering since morbidity and mortality rates ranging from 25%-50% persist among modern published series. Some of the most impactful variation in rAAA management has been fostered by the rapid proliferation of endovascular repair (EVAR) along with service alignment at selected centers to improve timely revascularization. Indeed, clinical care pathways and emergency response networks are now increasingly utilized which has led to improved outcomes contemporaneously. Moreover, evolution in pre- and post-operative physiologic resuscitation has also contributed to observed improvements in rAAA outcomes. Due to different developments in care provision over time, the purpose of this review is to describe the modern management of rAAA, while providing historical perspectives on patient, procedure and systems-based practice elements that have evolved care delivery paradigms in this complex group of patients.