The evolution of open abdominal aortic aneurysm repair at a tertiary care center

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.

Outcomes and Cost-Analysis of Open Versus Endovascular Abdominal Aortic Aneurysm Repair in a Developing Country: A 15-year Experience at a Tertiary Medical Center

BACKGROUND

Endovascular aortic aneurysm repair (EVAR) has become the most common procedure for treating abdominal aortic aneurysms based on multiple studies conducted in the western world. The implication of such findings in developing countries is not well demonstrated. The objective of this study was to compare medical outcomes and costs of EVAR and open surgical repair (OSR) in a developing country.

METHODS

This is a retrospective study of all patients undergoing elective abdominal aortic aneurysm repair between 2005 and 2020 at a tertiary medical center in a developing country. Medical records were used to retrieve demographics, comorbidities, and perioperative complications. Medical records were also used to provide data on the need of reintervention, date of last follow-up, and mortality.

RESULTS

The study included a total of 164 patients. Median follow-up time was 41 months. The mean age was 69.9 +/- 7.84 years and 90.24% (n = 148) of patients were males. Regarding long-term mortality outcomes, no significant difference was detected between both groups; OSR patients had a survival rate of 91.38% and 74.86% at 5 and 10 years, compared to 77.29% and 56.52% in the EVAR group (P value = 0.10). Both groups had comparable long-term reintervention rates (P value = 0.334). The OSR group was charged significantly less than the EVAR group ($27,666.35 vs. $44,528.04, P value = 0.008).

CONCLUSIONS

OSR and EVAR have comparable survival and reintervention outcomes. Unlike what was reported in developed countries, patients undergoing OSR in countries with low hospital stay costs incur lower treatment costs.

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.

Contemporary Indications for Open Abdominal Aortic Aneurysm Repair in the Endovascular Era

INTRODUCTION AND OBJECTIVES

Despite the emergence of endovascular aneurysm repair (EVAR) as the most common approach to abdominal aortic aneurysm repair, open aneurysm repair (OAR) remains an important option. This study seeks to define the indications for OAR in the EVAR era and how these indications effect outcomes.

METHODS

A retrospective cohort study was performed of all OAR at a single institution from 2004 to 2019. Pre-operative computed tomography scans and operative records were assessed to determine the indication for OAR. These reasons were categorized into anatomical contraindications; systemic factors (connective tissue disorders, contraindication to contrast dye); and patient/surgeon preference (patients who were candidates for both EVAR and OAR). Perioperative and long-term outcomes were compared between the groups.

RESULTS

370 patients were included in the analysis; 71.6% (265/370) had at least one anatomic contraindication to EVAR; 36% had two or more contraindications. The most common anatomic contraindications were short aortic neck length (51.6%), inadequate distal seal zone (19.2%), and inadequate access vessels (15.7%). The major perioperative complication rate was 18.1% and the 30-day mortality was 3.0%. No single anatomic factor was identified as a predictor of perioperative complications. Sixty-one patients (16.5%) had OAR based on patient/surgeon preference; these patients were younger; had lower incidences of coronary artery disease and chronic obstructive pulmonary disease; and they were less likely to require suprarenal cross clamping compared with patients who had anatomic and/or systemic contraindications to EVAR. The patient/surgeon preference group had a lower incidence of perioperative major complications (8.2% versus 20.1%, p=0.034), shorter length of stay (6 versus 8 days, p<0.001) and zero 30-day mortalities. The multivariable adjusted risk for 15-year mortality was lower for patient/surgeon preference patients (adjusted hazard ratio 0.44 [95% confidence interval 0.24-0.80], p=0.007) compared to those anatomic/systemic contraindications.

CONCLUSIONS

Within a population of patients who did not meet instruction for use (IFU) criteria for EVAR, no single anatomic contraindication was a marker for worse outcomes with OAR. Patients who were candidates for both aortic repair approaches but elected to have open surgical repair due to patient/surgeon preference have very low 30-day mortality and morbidity, and superior long-term survival rates compared with those patients who had OAR due to anatomic and/or systemic contraindications to EVAR.

Evaluating Proximal Clamp Site and Intraoperative Ischemia Time Among Open Repair of Juxtarenal Aneurysms

INTRODUCTION

The proportion of open aneurysm repairs requiring at least a suprarenal clamp has increased in the past few decades, partly due to preferred endovascular approaches for most patients with infrarenal aneurysms, suggesting that the management of aortic clamp placement has become even more relevant. This study evaluated the association between proximal clamp site and intraoperative ischemia times with postoperative renal dysfunction and mortality.

METHODS

We used the Vascular Quality Initiative to identify all patients undergoing open repairs of elective or symptomatic juxtarenal AAAs from 2004-2018 and compared outcomes by clamp site: above one renal artery, above both renal arteries (supra-renal), or above the celiac trunk (supra-celiac). Outcomes evaluated included acute kidney injury (AKI), new-onset renal failure requiring renal replacement therapy (RRT), 30-day mortality, and one-year mortality. We used multilevel logistic regressions and cox-proportional hazards models, clustered at the hospital level, to adjust for confounding.

RESULTS

We identified 3976 patients (median age 71 years, 70% male, 8.2% non-Caucasian), with a median aneurysm diameter of 5.9cm (IQR 5.4-6.8cm). Proximal clamp sites were: above one renal artery (31%), supra-renal (52%), and supra-celiac (17%). Rates of unadjusted outcomes were 20.5% for AKI, 4.1% for new-onset RRT, 4.9% for 30-day mortality, and 8.3% for one-year mortality. On adjusted analyses, independent of ischemia time, supra-renal clamping relative to clamping above a single renal artery had higher odds of postoperative AKI (aOR 1.50 [95%-CI 1.28-1.75]) but similar odds for new-onset RRT (aOR 1.27 [0.79-2.06]) and 30-day mortality (aOR 1.12 [0.79-1.58]) and hazards for one-year mortality (aHR 1.12 [0.86-1.45]). However, every ten minutes of prolonged intraoperative ischemia time was associated with an increase in odds or hazards ratio of postoperative AKI by +7% (IQR 3-11%), new-onset RRT by +11% (IQR 4-17%), 30-day mortality by +11% (IQR 6-17%), and one-year mortality by +7% (IQR 2-13%). Patients with greater than 40 minutes of ischemia time had notably higher rates of all four outcomes.

DISCUSSION

Supra-renal clamping relative to clamping above a single renal artery was associated with AKI but not new-onset RRT or 30-day mortality. However, intraoperative renal ischemia time was independently associated with all four postoperative outcomes. While further studies are warranted, our findings suggest that an expeditious proximal anastomosis creation is more important than trying to maintain clamp position below one renal artery, suggesting that suprarenal clamping may be the best strategy for open AAA repair when needed to efficiently perform the proximal anastomosis.

EVAR Conversion is an Increasingly Common Indication for Open AAA Repair

OBJECTIVE

Although EVAR re-intervention is common, conversion to open repair(EVAR-c) occurs less frequently but can be associated with significant technical complexity and perioperative risk. There is a paucity of data highlighting the evolution of peri-procedural results surrounding EVAR-c and change in practice patterns, especially for referral centers that increasingly manage EVAR failures. The purpose of this analysis was to perform a temporal analysis of our EVAR-c experience and describe changes in patient selection, operative details and outcomes.

METHODS

A retrospective single center review of all open AAA repairs was performed(2002-2019) and EVAR-c procedures were subsequently analyzed. EVAR-c patients(n=184) were categorized into two different eras(2002-2009, n=21; 2010-2019, n=163) for comparison. Logistic regression and Cox proportional hazards modeling were used for risk-adjusted comparisons.

RESULTS

A significant increase in EVAR-c as an indication for any type of open aneurysm repair was detected(9%→27%;p<.001). Among EVAR-c patients, no change in age or individual comorbidities was evident[mean age: 71±9 years]; however, the proportion of female subjects(p=.01) and ASA classification >3 declined(p=.05). There was no difference in prevalence[50% vs. 43%;p=.6] or number[median-1.5(0, 5)] of pre-admission EVAR re-interventions; however, time to re-intervention decreased(median: 23[6,34] vs. 0[0,22] months;p=.005). In contrast, time to EVAR-c significantly increased(median: 16[9,39]vs. 48[20,83]-months;p=.008). No difference in frequency of non-elective presentation[mean-52%;p=.9] or indication was identified but a trend toward increasing mycotic EVAR-c was observed(5% vs. 15%;p=.09). Use of retroperitoneal exposure(14% vs. 77%;p<.0001), suprarenal cross-clamp application[6286%;p=.04] and visceral-ischemia time(median: 0[0,11] vs. 5[0,20]min;p=.05) all increased. In contrast, estimated blood loss(P-trend=.03) and procedure-time(p=.008) decreased. The unadjusted elective 30-day mortality rate improved but did not reach statistical significance[elective: 10% vs. 5%;p=.5] with no change for non-elective operations[18% vs. 16%;p=.9]. However, a significantly decreased risk of complications was evident(OR 0.88, 95%CI .8-.9;p=.01). One and 3-year survival was similar over time.

CONCLUSION

EVAR-c is now a common indication for open AAA repair. Patients frequently present non-electively and at increasingly later intervals after their index EVAR. Despite increasing technical complexity, decreased complication risk and comparable survival can be anticipated when patients are managed at a high-volume aortic referral center.

Open Surgical Repair of Abdominal Aortic Aneurysms Maintains a Pivotal Role in the Endovascular Era

Since the advent of endovascular aortic repair (EVAR) nearly three decades ago, there has been a paradigm shift in the treatment of the abdominal aortic aneurysm (AAA) to favor EVAR due to its reduced operative mortality, less invasive nature, and faster recovery times. However, more recently there has been an accumulation of data from large meta-analyses and randomized clinical trials revealing that EVAR has no survival benefit after approximately 2 years and is associated with substantially higher rates of reintervention and aneurysm rupture in the long term. These findings call into question the durability of EVAR compared with open aortic repair and emphasize the need for surgeons to remain competent with open aortic surgery in the modern era. This article will provide comprehensive review of a large body of literature comparing endovascular repair to open aortic surgery for the management of AAAs, and it will offer an overview of the open surgical repair technique for AAAs.